merge Mesa 7.8.2.

import Mesa 7.8.2, glut part. major changes since 7.7.1:
- several new extensions for various drivers
- many i965, i915 driver fixes
- many glsl fixes

merge MesaGLUT 7.7.1

initial import of MesaGLUT-7.7.1

initial import of MesaGLUT-7.4.2

Initial import of MesaGLUT, version 7.0.3 for native X.Org's benefit.