[Mesa-dev] UBO support

[vlj]

This set of patches add partial support for Uniform Buffer Object (UBO) in mesa.
This is still Work In Progress so the last 3 patches are not complete yet, and support from the driver is not done yet. The first 6 patches however can be reviewed.

I did not implement UBO "inside shader name" and array of UBO, because they are said to be deferred for another extension. 
Bison file should not yield reduce/map or reduce/reduce conflict.

The spec about UBO is here :
http://www.opengl.org/registry/specs/ARB/uniform_buffer_object.txt

Regards,
Vincent