Clarify How To Use Action Options When Selecting More Than One User

Issue Summary

Usage of the actions options should be clarified in the documentation:

For administrators wondering why nothing happens (no users listed) when you try to apply an action to a selected group of users, do the following: If you're trying to complete an action after selecting more than one user (ie delete selected users, ban selected users, etc.), you must first must choose the 'Save selection criteria' , THEN reselect the action you're trying to complete and click 'Apply Action'.

I'm guessing that this is actually intended to be a feature -- so that you can page through several pages of users without losing your selections (?) -- but I really thought this module wasn't working when I first installed it -- (In fact, I thought the message next to action reading 'No selected users have been saved.' was actually a bug). But if you complete the first step, everything works fine.

Come to think of it, if no users appear when you choose an action, some sort of message should show up saying something like, "Before applying group operations, you must select 'Save Selection Criteria.'" That would go a long way to lowering the learning curve on this module.