gsdx: 
* try to setup advance gl context attribute. If driver doesn't support it fallback to the default.

zzogl:
* use glsl2h to generate an header shader as GSdx. Much easier to install
* Get GSUniformBufferOGL & GSVertexArrayOGL speed improvement from GSdx

cmake:
* detect current gcc version. Yield  a warning if < 4.7 or an error if < 4.5

glsl2h:
* support zzogl too
* compute md5sum to avoid useless relink


git-svn-id: http://pcsx2.googlecode.com/svn/trunk@5696 96395faa-99c1-11dd-bbfe-3dabce05a288
gsdx: split shader/program/pipeline object management into a separate class
* remove the possibility to compile shader from file. Some people loads older shaders...
  The feature might be readded later


git-svn-id: http://pcsx2.googlecode.com/svn/trunk@5697 96395faa-99c1-11dd-bbfe-3dabce05a288