Revert "manifest: Tag cogl"

This reverts commit a114666aae726b878d2da1ccc8337e7d1bde0fcd.

<buildgnomeorg> continuous:build 20131211.51: failed in 36.2 seconds.
failed: clutter
http://build.gnome.org/continuous/buildmaster/builds/2013/12/11/51/build/
<mclasen> hmm, cogl didn't get built ?
<halfline> could it be walters forced it to a specific commit id because
of some breakage ?
<halfline>
https://git.gnome.org/browse/gnome-continuous/commit/?id=a114666aae726b878d2da1ccc8337e7d1bde0fcd
<halfline> so when this got reverted:
https://git.gnome.org/browse/gnome-continuous/commit/?id=821cc81f8ac0c79f86475d0e57e43665d929d5d6
the cogl bits probably should have been reverted too
<mclasen> could be
<mclasen> no, cogl was intentionally left tagged
<mclasen> but I think we're over that now
<halfline> well since walters isn't chiming in, let's revert it and see
if things get better or worse
manifest: Tag both cogl and clutter