Adds missing notices, and ensures all the notices are consistent. The Cogl
blurb also now reads:
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
Bug 980 - cogl-bitmap-fallback.c compiler error/warning due to
cast issue (Haakon Sporsheim)
* clutter/cogl/common/cogl-bitmap-fallback.c:
(_cogl_unpremult_alpha_last),
(_cogl_unpremult_alpha_first): Cast to avoid a compiler warning
with MSC.