Bot interrupts

[bad_captain]

In mob::SpellCastedFinished is the check to interrupt. There is an isClient check that uses channeling, etc, but bots use the default npc interrupt code which doesnt. The biggest difference however is that npcs lose 1% chance to channel per hit whereas clients lose 2%. I've added in a fix but wont get checked in for a few days as I' m testing a few other things. But honestly, I think there's not much difference in the end result (within 10-20%) so I don't think you'll see a huge change. If I read the code correctly, at max channeling (which bots have) there's still a ~60% chance to channel when being completely beat on while casting. - the number of hits that count against channeling is capped at 15.