Groups ui upgrade

This updates the existing groups UI to use the multiselect widget. It's quite a bit more compact and also more usable, since it doesn't hit the server everytime the membership changes. Read commit by commit.

This is in QA / UA so will close for review for now.

![image](https://f.cloud.github.com/assets/66555/1151793/d99a1f36-1f00-11e3-9077-059333b60f63.png)