edje: add collection.group.limits.vertical and collection.group.limits.horizontal.

edje: add collection.group.limits.vertical and collection.group.limits.horizontal.

The goal is to provide an easy way to do the kind of effect you see in that video
around 00:36 : http://www.youtube.com/watch?v=KVoVLHh8CHc.
  At that time it was really difficult to do such thing and required a lot of
embryo code, we designed limit with Billiob to be able to do such kind of things
much more easily.

NOTE: so Billiob, now nothing stop you from releasing amsn2 ! ;-)

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/edje@62701 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33