Add iLogic functions for handling Event Triggers

[DRoam]

Currently there are no iLogic functions which will do what the above mock-up code does: handle the Event Triggers. Many iLogic rules are designed to automate tasks. As such, it would be great if a rule could check for itself (or another rule) is in the Event Triggers, and add it if not present. Of course, it would also be handy if we could check for and remove rules from a trigger as well.

This would fill a big gap in iLogic's ability to automate tasks.

[t3dris]

This is absolutely needed!

This should incluse external rules aswell of course!