Allow small timeout intervals in IdleInterface

A threshold exists to stop users flooding the server for no reason.

However, there is a usecase for small timeouts.

rsibreak has a "please relax for 20 seconds" interface. Here it makes
perfect sense to know if a user is active in small increments. The plan
is to start a 1s timer and wait for that. Then we wait locally for 20s
without a resume event.