Spell effect additions.

Kayen: Implemented SE_ReduceHealing (Reduces amount of healing on target by X amount)
Kayen: Implemented SE_CastonFocusEffect (Triggers spell as part of a focus, when that focus effect is used)
Kayen: Implemented SE_IncreaseHitDmgTaken (Effect is triggered when X amount of damage is taken)
Kayen: More fixes for various spell triggers/procs to now properly use their resist modifier.