Bug 1074 - FBOs on GLES

	Bug 1074 - FBOs on GLES

	* clutter/cogl/gles/cogl-fbo.c: Copy the code from gl/cogl-fbo but
	use the API calls directly instead of loading an extension because
	it is part of the core in GLES 2.

	* clutter/cogl/gles/cogl.c (_cogl_features_init): Report
	COGL_FEATURE_OFFSCREEN.

	* clutter/cogl/gles/cogl-fbo.h (CoglFbo): Add gl_stencil_handle.

	* clutter/cogl/gles/cogl-context.h (CoglContext): Add
	viewport_store

	* tests/test-fbo.c (make_shader): Conditionally use the GLES 2
	names of the shader variables