This might be dangerous, not applying to trunk/stable yet.

Conflicts:

	htdocs/lib/view.php
	htdocs/view/groupviews.php

* Remove a couple of functions from the group libs that are only used in one or two places:
 - get_owned_groups was only used on user/view and for the sideblock showing the groups you owned. We're going to show more than that now, meaning the function is wasted indirection for the one remaining place it would be used.
 - get_tutor_groups was only used on user/view, and has been broken by the group schema changes.
* Fix adding users to controlled communities. Still have to provide the ability to do this by dropdown.
* Fixed a bug caused by my misunderstanding of how (array) false works - it seems to make an array with 'false' as one value.

Prevent a crash when a group has no forum posts in it. Fix up some language strings on the group info page too.

Even though the code to implement getting strings from that place is not implemented yet :)