Usergroup Classification Control

[talenak]

I'd like to be able to control whether a usergroup can be classified as primary and or secondary only.

We only use 3 primary usergroups.

We'll be using lots more secondary groups, and I would like to not have every single group showing up in the search options for primary and secondary. It's just a lot of redundancy.

It will also eliminate potential for accidentally changing someone from the primary usergroup they are supposed to be in and hiding them from mailing lists because they weren't set correctly.

I've searched really hard to make sure I wasn't requesting something already there, but feel free to backhand me if I overlooked something!