[12515] EventAI: Implement ACTION_T_SET_THROW_MASK (46)

This Action can be used to set which AIEvents should be thrown automatically, if you need more flexibility, you can always use the manual ACTION_TH_THROW_AI_EVENT version.

* Also clean some error-log output a bit.
[12516] EventAI: Improve code

* Drop rather pointless bool to check if the number of assigned events is empty
* Before the phase was resetted on death if and only if the npc has Events defined
* DoMeleeAttackIfReady could have been called even though combat state could have changed while processing events