We weren't defining CLUTTER_CEX100_LIBGDL_PREFIX in the configure.ac and
thus failing to compile when selecting the EGL/GDL winsys. Take the
opportunity to rename that to COGL_CEX100_LIBGDL_PREFIX
https://bugzilla.gnome.org/show_bug.cgi?id=655355
The changelog generation scripts used for releases are overly elaborate
and fragile. A Changelog is also no substitute for the Git log so now we
simply ship a static Changelog that points to the Git log instead.
This explicitly renames the cogl-2.0 reference manual to
cogl-2.0-experimental and renames the cogl-2.0 pkg-config file to
cogl-2.0-experimental.pc. Hopefully this should avoid
miss-understandings.
