This commit pushes --disable-glib to the extreme of embedding the par of
glib cogl depends on in tree to be able to generate a DSO that does not
depend on an external glib.
To do so, it:
- keeps a lot of glib's configure.ac in as-glibconfig.m4
- pulls the code cogl depends on and the necessary dependencies
Reviewed-by: Robert Bragg <robert@linux.intel.com>