mesa-resources: Basic stuff, scripts, and so on used when hacking on mesa

A brief description of what it contains:

 * jhbuild: a custom moduleset, and a template jhbuildrc file for mesa
   and piglit building

 * deqp: basic stuff for deqp.

 * piglit: basic stuff for piglit.

 * testing: tools and scripts to use while testing.

 * gnome-session: tools to run GNOME with your desired GL driver