Add a config.h for Windows.
Don't prefix includes in graphviz-static.
Some build fixes for linux.
We need -fPIC whenever we compile an archive that subsequently is combined into a .so, but CMake doesn't do this by default. Thus, we preferentially build .so's, and when we have to build .a's (to break cycles), we manually set -fPIC.
Add a method to initialise graphviz using the preloaded symbols.
Misc small build improvements.
Add the CMake build system (and a statics file).
Add graphviz 2.28.