Remove setting of precisions in GLES2
Specify precision explicitly (for GLES2)
Revert "Specify precision explicitly (for GLES2)"

This reverts commit 1bbaadd0d99cb1d33c6577ec1d6441e34bc1a7d3.
Revert "Remove setting of precisions in GLES2"

This reverts commit 4416e07ca8ed6a3931090e1e3c26f98f28b3fd56.
remove useless constant
More correct tests state management
Optimize a bit map stage fragment shader for GLES2
glClearDepth_f_
Re-enable fog
Make fog code in map stage more readable
Simplify map stage fog expression a bit
Fix layers blending
Add GLSL optimizer from https://github.com/aras-p/glsl-optimizer
Fix glsl optimizer build
Move #extension upper
This optimizer makes things even worse
Very very dump error
Last chance for fog
Remove fog in it's current form, it consumes too much
Ask to generate best mipmaps possible