RFE: Provide selection boxes to manage multiple users

Due to bug #71 and bug #73, I've had to mass-change quota settings for multiple users more than once now. This has been very inconvenient with the current user table, since they must be selected and changed one at a time. This task would be much easier in the future if selection boxes were provided to change quotas for multiple users all at once.

Status: 
Closed (fixed)