Platform needs to list required C libraries in INSTALL file

[r0ml]

The platform will depend on a number of C libraries. These dependencies , and their versions, need to be precisely stated.

[r0ml]

Here's a few: * OpenGL * GLUT * OpenAL

And I guess that's all, cause zlib is self-contained.

Actually it needs the system zlib on all platforms except Windows. The generic tarball configure script now checks for all of these.

Individual packages may or may not list their C libs. We need to work out what the story is.

See #63

[gbaz]

related to #145