* clutter/Makefile.am:
* clutter/clutter-feature.c:
* clutter/clutter-feature.h:
Add new funcs for checking for available runtime GL
extensions.
* clutter/clutter-clone-texture.c:
* clutter/clutter-texture.c:
Add support for non power of two textures
if GL_TEXTURE_RECTANGLE_ARB extension available ( at runtime ).
Should lower texture memory needs a little.
