Add a "momentary/toggle" option to sensors

[macinspak]

Or create different sensor types.

A "momentary" sensor is like a motion sensor. The sensor triggers and then times out.

A "Toggle" sensor is like a NC or NO sensor, it's either an open door that is left open (so it doesn't keep getting messages, but has a personal state that persists until another messages says it's now closed.

At the moment there is only a trigger for when a state changes, but not one where it remains in an alarm state (like a door left open).