* Make build system honour the proper ABI library directory.
* Replace -isystem arguments with -I, as the former causes issues with GCC 6.
  See also:
  https://bugs.gentoo.org/show_bug.cgi?id=597866
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70129

--- a/doxygen-config
+++ b/doxygen-config
@@ -2257,7 +2257,7 @@
 # The default value is: png.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-DOT_IMAGE_FORMAT       = png
+DOT_IMAGE_FORMAT       = svg
 
 # If DOT_IMAGE_FORMAT is set to svg, then this option can be set to YES to
 # enable generation of interactive SVG images that allow zooming and panning.
--- a/Makefile
+++ b/Makefile
@@ -82,6 +82,7 @@
 
 # The directory into which to install libraries, executables and header files
 DESTDIR := /tmp/OpenVDB
+libdir = lib
 
 # The parent directory of the boost/ header directory
 BOOST_INCL_DIR := $(HT)/include
@@ -158,6 +159,9 @@
 # The directory containing libpython
 PYTHON_LIB_DIR := $(HFS)/python/lib
 PYTHON_LIB := -lpython$(PYTHON_VERSION)
+# The Directory to install the python module and includes to.
+PYTHON_INSTALL_INCL_DIR := $(DESTDIR)/python/include/python$(PYTHON_VERSION)
+PYTHON_INSTALL_LIB_DIR := $(DESTDIR)/python/lib/python$(PYTHON_VERSION)
 # The directory containing libboost_python
 BOOST_PYTHON_LIB_DIR := /rel/depot/third_party_build/boost/rhel6-1.46.1-0/lib
 BOOST_PYTHON_LIB := -lboost_python-gcc41-mt-python26-1_46_1
@@ -179,7 +183,6 @@
 # (leave blank if Doxygen is unavailable)
 DOXYGEN := doxygen
 
-
 #
 # Ideally, users shouldn't need to change anything below this line.
 #
@@ -207,11 +210,7 @@
     endif
 endif
 
-ifeq (yes,$(strip $(debug)))
-    OPTIMIZE := -g
-else
-    OPTIMIZE := -O3 -DNDEBUG
-endif
+OPTIMIZE := -DNDEBUG
 
 ifeq (yes,$(strip $(verbose)))
     QUIET :=
@@ -242,12 +241,12 @@
     has_python := yes
 endif
 
-INCLDIRS := -I . -I .. -isystem $(BOOST_INCL_DIR) -isystem $(ILMBASE_INCL_DIR) -isystem $(TBB_INCL_DIR)
+INCLDIRS := -I. -I.. -I$(BOOST_INCL_DIR) -I$(ILMBASE_INCL_DIR) -I$(TBB_INCL_DIR)
 ifeq (yes,$(has_blosc))
-    INCLDIRS += -isystem $(BLOSC_INCL_DIR)
+    INCLDIRS += -I$(BLOSC_INCL_DIR)
 endif
 ifeq (yes,$(has_log4cplus))
-    INCLDIRS += -isystem $(LOG4CPLUS_INCL_DIR)
+    INCLDIRS += -I$(LOG4CPLUS_INCL_DIR)
 endif
 
 CXXFLAGS += -std=c++0x
@@ -565,9 +564,9 @@
     python/pyTransform.cc \
     python/pyVec3Grid.cc \
 #
-PYCXXFLAGS := -fPIC -isystem python -isystem $(PYTHON_INCL_DIR) -isystem $(PYCONFIG_INCL_DIR)
+PYCXXFLAGS := -fPIC -Ipython -I$(PYTHON_INCL_DIR) -I$(PYCONFIG_INCL_DIR)
 ifneq (,$(strip $(NUMPY_INCL_DIR)))
-PYCXXFLAGS += -isystem $(NUMPY_INCL_DIR) -DPY_OPENVDB_USE_NUMPY
+PYCXXFLAGS += -I$(NUMPY_INCL_DIR) -DPY_OPENVDB_USE_NUMPY
 endif
 ifneq (no,$(strip $(PYTHON_WRAP_ALL_GRID_TYPES)))
 PYCXXFLAGS += -DPY_OPENVDB_WRAP_ALL_GRID_TYPES
@@ -678,7 +677,7 @@
 	@echo "Building $@ because of $(call list_deps)"
 	$(CXX) -c $(CXXFLAGS) -fPIC -o $@ $<
 
-all: lib python vdb_print vdb_render vdb_test depend
+all: lib python vdb_print vdb_render vdb_view vdb_test depend
 
 $(OBJ_NAMES): %.o: %.cc
 	@echo "Building $@ because of $(call list_deps)"
@@ -719,8 +718,13 @@
 	@echo "Generating documentation because of $(list_deps)"
 	echo -e 'OUTPUT_DIRECTORY=./doc\nGENERATE_LATEX=YES\nGENERATE_HTML=NO' \
 	    | cat doxygen-config - | $(DOXYGEN) - $(QUIET) \
-	    && cd ./doc/latex && make refman.pdf $(QUIET) \
+	    && cd ./doc/latex && $(MAKE) refman.pdf $(QUIET) \
 	    && echo 'Created doc/latex/refman.pdf'
+	@#
+	    mkdir -p $(DESTDIR)/share/doc/openvdb/pdf; \
+	    echo "Created $(DESTDIR)/share/doc/openvdb/pdf"; \
+	    cp -r -f doc/latex/refman.pdf $(DESTDIR)/share/doc/openvdb/pdf/; \
+	    echo "Copied documentation to $(DESTDIR)/share/doc/openvdb/pdf/"; \
 
 ifneq (,$(strip $(DOXYGEN)))
 doc: $(DOC_INDEX)
@@ -734,14 +738,14 @@
 
 vdb_print: $(LIBOPENVDB) cmd/openvdb_print/main.cc
 	@echo "Building $@ because of $(list_deps)"
-	$(CXX) $(CXXFLAGS) -o $@ cmd/openvdb_print/main.cc -I . \
+	$(CXX) $(CXXFLAGS) -o $@ cmd/openvdb_print/main.cc -I. \
 	    $(LIBOPENVDB_RPATH) -L$(CURDIR) $(LIBOPENVDB) \
 	    $(LIBS_RPATH) $(CONCURRENT_MALLOC_LIB)
 
 vdb_render: $(LIBOPENVDB) cmd/openvdb_render/main.cc
 	@echo "Building $@ because of $(list_deps)"
-	$(CXX) $(CXXFLAGS) -o $@ cmd/openvdb_render/main.cc -I . \
-	    -isystem $(EXR_INCL_DIR) -isystem $(ILMBASE_INCL_DIR) \
+	$(CXX) $(CXXFLAGS) -o $@ cmd/openvdb_render/main.cc -I. \
+	    -I$(EXR_INCL_DIR) -I$(ILMBASE_INCL_DIR) \
 	    -Wl,-rpath,$(EXR_LIB_DIR) -L$(EXR_LIB_DIR) $(EXR_LIB) \
 	    -Wl,-rpath,$(ILMBASE_LIB_DIR) -L$(ILMBASE_LIB_DIR) $(ILMBASE_LIB) \
 	    $(LIBOPENVDB_RPATH) -L$(CURDIR) $(LIBOPENVDB) \
@@ -761,12 +765,12 @@
 $(LIBVIEWER_OBJ_NAMES): $(LIBVIEWER_INCLUDE_NAMES)
 $(LIBVIEWER_OBJ_NAMES): %.o: %.cc
 	@echo "Building $@ because of $(list_deps)"
-	$(CXX) -c $(CXXFLAGS) -I . -isystem $(GLFW_INCL_DIR) -DGL_GLEXT_PROTOTYPES=1 -fPIC -o $@ $<
+	$(CXX) -c $(CXXFLAGS) -I. -I$(GLFW_INCL_DIR) -DGL_GLEXT_PROTOTYPES=1 -fPIC -o $@ $<
 
 vdb_view: $(LIBOPENVDB) $(LIBVIEWER_OBJ_NAMES) cmd/openvdb_view/main.cc
 	@echo "Building $@ because of $(list_deps)"
 	$(CXX) $(CXXFLAGS) -o $@ cmd/openvdb_view/main.cc $(LIBVIEWER_OBJ_NAMES) \
-	    -I . -Wl,-rpath,$(GLFW_LIB_DIR) -L$(GLFW_LIB_DIR) $(GLFW_LIB) \
+	    -I. -Wl,-rpath,$(GLFW_LIB_DIR) -L$(GLFW_LIB_DIR) $(GLFW_LIB) \
 	    $(LIBOPENVDB_RPATH) -L$(CURDIR) $(LIBOPENVDB) \
 	    $(LIBVIEWER_FLAGS) $(LIBS_RPATH) $(BOOST_THREAD_LIB) $(CONCURRENT_MALLOC_LIB)
 endif
@@ -776,7 +780,7 @@
 $(PYTHON_OBJ_NAMES): $(PYTHON_INCLUDE_NAMES)
 $(PYTHON_OBJ_NAMES): %.o: %.cc
 	@echo "Building $@ because of $(list_deps)"
-	$(CXX) -c $(CXXFLAGS) -I . $(PYCXXFLAGS) -o $@ $<
+	$(CXX) -c $(CXXFLAGS) -I. $(PYCXXFLAGS) -o $@ $<
 $(PYTHON_MODULE): $(LIBOPENVDB) $(PYTHON_OBJ_NAMES)
 	@echo "Building $@ because of $(list_deps)"
 	$(CXX) $(CXXFLAGS) $(PYCXXFLAGS) -shared $(PYTHON_SONAME_FLAGS) -o $@ $(PYTHON_OBJ_NAMES) \
@@ -784,6 +788,22 @@
 	    -Wl,-rpath,$(BOOST_PYTHON_LIB_DIR) -L$(BOOST_PYTHON_LIB_DIR) $(BOOST_PYTHON_LIB) \
 	    $(LIBOPENVDB_RPATH) -L$(CURDIR) $(LIBOPENVDB) \
 	    $(LIBS_RPATH) $(CONCURRENT_MALLOC_LIB)
+	@echo "Installing the python module and includes"
+	@#
+	    mkdir -p $(PYTHON_INSTALL_INCL_DIR); \
+	    echo "Created $(PYTHON_INSTALL_INCL_DIR)"; \
+	    cp -f $(PYTHON_PUBLIC_INCLUDE_NAMES) $(PYTHON_INSTALL_INCL_DIR)/; \
+	    echo "Copied Python header files to $(PYTHON_INSTALL_INCL_DIR)"; \
+	    mkdir -p $(PYTHON_INSTALL_LIB_DIR); \
+	    echo "Created $(PYTHON_INSTALL_LIB_DIR)"; \
+	    cp -f $(PYTHON_MODULE) $(PYTHON_INSTALL_LIB_DIR)/; \
+	    pushd $(PYTHON_INSTALL_LIB_DIR) > /dev/null; \
+	    ln -f -s $(PYTHON_MODULE) $(PYTHON_SONAME); \
+	    popd > /dev/null; \
+	    echo "Copied Python module to $(PYTHON_INSTALL_LIB_DIR)"
+	@echo "Clean the Python modules so the next one will compile"
+	@#
+	    $(RM) $(PYTHON_OBJ_NAMES)
 
 ifeq (yes,$(has_python))
 ifneq (,$(strip $(EPYDOC)))
@@ -794,7 +814,7 @@
 	echo "Created $${pydocdir}"; \
 	export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$(CURDIR); \
 	export PYTHONPATH=${PYTHONPATH}:$(CURDIR); \
-	    $(EPYDOC) --html -o $${pydocdir} $(PYTHON_MODULE_NAME) $(QUIET)
+	    $(EPYDOC) --html --html-dir $${pydocdir} $(PYTHON_MODULE_NAME) $(QUIET)
 else
 pydoc:
 	@echo "$@"': $$EPYDOC is undefined'
@@ -815,7 +835,7 @@
 
 $(UNITTEST_OBJ_NAMES): %.o: %.cc
 	@echo "Building $@ because of $(list_deps)"
-	$(CXX) -c $(CXXFLAGS) -isystem $(CPPUNIT_INCL_DIR) -fPIC -o $@ $<
+	$(CXX) -c $(CXXFLAGS) -I$(CPPUNIT_INCL_DIR) -fPIC -o $@ $<
 
 ifneq (,$(strip $(CPPUNIT_INCL_DIR)))
 vdb_test: $(LIBOPENVDB) $(UNITTEST_OBJ_NAMES)
@@ -835,7 +855,7 @@
 	@echo "$@"': $$(CPPUNIT_INCL_DIR) is undefined'
 endif
 
-install: lib python vdb_print vdb_render vdb_view doc pydoc
+install: lib vdb_print vdb_render vdb_view doc pydoc
 	mkdir -p $(DESTDIR)/include/openvdb
 	@echo "Created $(DESTDIR)/include/openvdb"
 	pushd $(DESTDIR)/include/openvdb > /dev/null; \
@@ -851,42 +871,25 @@
 	fi
 	@echo "Copied header files to $(DESTDIR)/include"
 	@#
-	mkdir -p $(DESTDIR)/lib
-	@echo "Created $(DESTDIR)/lib/"
-	cp -f $(LIBOPENVDB) $(DESTDIR)/lib
-	pushd $(DESTDIR)/lib > /dev/null; \
+	mkdir -p $(DESTDIR)/$(libdir)
+	@echo "Created $(DESTDIR)/$(libdir)/"
+	cp -f $(LIBOPENVDB) $(DESTDIR)/$(libdir)
+	pushd $(DESTDIR)/$(libdir) > /dev/null; \
 	    if [ -f $(LIBOPENVDB_SHARED) ]; then \
 	        ln -f -s $(LIBOPENVDB_SHARED) $(LIBOPENVDB_SHARED_NAME); \
 	        ln -f -s $(LIBOPENVDB_SHARED) $(LIBOPENVDB_SONAME); \
 	    fi; \
 	    popd > /dev/null
-	@echo "Copied libopenvdb to $(DESTDIR)/lib/"
+	@echo "Copied libopenvdb to $(DESTDIR)/$(libdir)/"
 	@#
 	if [ -f $(LIBVIEWER) ]; \
 	then \
-	    cp -f $(LIBVIEWER) $(DESTDIR)/lib; \
-	    pushd $(DESTDIR)/lib > /dev/null; \
+	    cp -f $(LIBVIEWER) $(DESTDIR)/$(libdir); \
+	    pushd $(DESTDIR)/$(libdir) > /dev/null; \
 	        if [ -f $(LIBVIEWER_SHARED) ]; then \
 	            ln -f -s $(LIBVIEWER_SHARED) $(LIBVIEWER_SHARED_NAME); fi; \
 	        popd > /dev/null; \
-	    echo "Copied libopenvdb_viewer to $(DESTDIR)/lib/"; \
-	fi
-	@#
-	if [ -f $(PYTHON_MODULE) ]; \
-	then \
-	    installdir=$(DESTDIR)/python/include/python$(PYTHON_VERSION); \
-	    mkdir -p $${installdir}; \
-	    echo "Created $${installdir}"; \
-	    cp -f $(PYTHON_PUBLIC_INCLUDE_NAMES) $${installdir}/; \
-	    echo "Copied Python header files to $${installdir}"; \
-	    installdir=$(DESTDIR)/python/lib/python$(PYTHON_VERSION); \
-	    mkdir -p $${installdir}; \
-	    echo "Created $${installdir}"; \
-	    cp -f $(PYTHON_MODULE) $${installdir}/; \
-	    pushd $${installdir} > /dev/null; \
-	    ln -f -s $(PYTHON_MODULE) $(PYTHON_SONAME); \
-	    popd > /dev/null; \
-	    echo "Copied Python module to $${installdir}"; \
+	    echo "Copied libopenvdb_viewer to $(DESTDIR)/$(libdir)/"; \
 	fi
 	@#
 	mkdir -p $(DESTDIR)/bin
@@ -924,7 +927,7 @@
 	    for f in $(UNITTEST_SRC_NAMES); \
 	        do $(CXX) $(CXXFLAGS) -O0 \
 	            -MM $$f -MT `echo $$f | sed 's%\.[^.]*%.o%'` \
-	            -isystem $(CPPUNIT_INCL_DIR) >> $(DEPEND); \
+	            -I$(CPPUNIT_INCL_DIR) >> $(DEPEND); \
 	    done; \
 	fi