Update User and Group model validation for K3.
Add "write_only" option to our Formo/ORM linking driver - useful for passwords.
Revise pagination links in View_Gallery.
Big rewrite of Controller_Admin_Users for K3/Formo/Pagination - it all works!
- revised for K3, new Pagination, and Formo.
- streamlined 14 routes down to 8.
- increased sanity checks around add/remove users from groups actions.
- used sub-request for showing the group instead of re-defining the view.
- removed separate delete confirmation dialog - new templates don't need it.
- cleaned up error messages (some missing, others redefined from K2, etc.).
Clean up some no-longer-needed lines in Controller_Items.
Big rewrite of Controller_Users for K3 and Formo.
- revised for K3 and Formo.
- streamlined 6 routes down to 3.
- used callbacks to Controller_Users_Admin for form definitions.
Merge pull request #362 from shadlaws/fixes_20130511

Fixes 20130511