Allow Crowd admins to disable / remove users when the license limit is exceeded

Problem Definition

When the license limit is exceed, Crowd locks up and prevents authentication until the license is upgraded.

Suggested Solution

To prevent outages, it would be very useful to prevent this from happening in the first place, and displaying a warning when a user will cause the license to go over the limit.

Notes

There currently is a warning email when 90% of the license count is being used up: Licensing.