Make macros for header file names optional.

We no longer have to take care of the 8.3 file name limit; this
allows us (a) to introduce longer, meaningful file names, and (b) to
avoid macro names in `#include' lines altogether since some
compilers (most notably Visual C++) doesn't support this properly.

*/*: Replace

   #include FOO_H


   #include <freetype/foo.h>

or something similar.  Also update the documentation.
330 files changed