Add C89 support

Allow compilation from C89 compilers.

.gitignore

@@ -0,0 +1,119 @@
+# Only include required source files.
+# Do no include any binaries or libraries/external sources.
+# Submodules are not added here, as they are managed by Git automatically.
+*
+*/
+
+# /
+!.gitignore
+!.gitmodules
+!AUTHORS
+!build.sh
+!CHANGELOG
+!configure.ac
+!INSTALL
+!LICENSE
+!Makefile.am
+!NEWS
+!README
+!TODO
+!config.mk
+!Changelog
+!LIMITATIONS
+!Makefile
+!README.BEOS
+
+# /BeOS
+!/BeOS/
+/BeOS/*
+
+!/BeOS/GLView.cpp
+!/BeOS/GLView.h
+!/BeOS/Makefile
+
+# /docs
+!/doc/
+/doc/*
+
+# /docs/1.0_LEGAl
+!/doc/1.0_LEGAL
+/doc/1.0_LEGAL/*
+
+!/doc/1.0_LEGAL/1.1_ACKNOWLEDGMENTS
+
+# /examples
+!/examples/
+/examples/*
+
+!/examples/gears.c
+!/examples/glu.c
+!/examples/glu.h
+!/examples/Makefile
+!/examples/mech.c
+!/examples/nanox.c
+!/examples/spin.c
+!/examples/texobj.c
+!/examples/ui.h
+!/examples/x11.c
+
+# /include
+!/include/
+/include/*
+
+!/include/GLView.h
+
+# /include/GL
+!/include/GL
+/include/GL/*
+
+!/include/GL/gl.h
+!/include/GL/glx.h
+!/include/GL/nglx.h
+!/include/GL/oscontext.h
+
+# /lib
+!/lib/
+/lib/*
+
+!/lib/README
+
+# /src
+!/src/
+/src/*
+
+!/src/api.c
+!/src/arrays.c
+!/src/clear.c
+!/src/clip.c
+!/src/error.c
+!/src/get.c
+!/src/glx.c
+!/src/image_util.c
+!/src/init.c
+!/src/light.c
+!/src/list.c
+!/src/Makefile
+!/src/matrix.c
+!/src/memory.c
+!/src/misc.c
+!/src/msghandling.c
+!/src/msghandling.h
+!/src/nglx.c
+!/src/opinfo.h
+!/src/oscontext.c
+!/src/select.c
+!/src/specbuf.c
+!/src/specbuf.h
+!/src/texture.c
+!/src/vertex.c
+!/src/zbuffer.c
+!/src/zbuffer.h
+!/src/zdither.c
+!/src/zfeatures.h
+!/src/zgl.h
+!/src/zline.c
+!/src/zline.h
+!/src/zmath.c
+!/src/zmath.h
+!/src/ztriangle.c
+!/src/ztriangle.h