plan.txt

* All participants start at 'beginning' state
* Build participant order
* Determine participant's turn actions for current state:
  * NPCs look at NpcCombatActions::getForState()
  * Players call PlayerCombatActions::getForState()
  * Classed NPCs/Players add PlayerClass::getActionsForState
  * Effects can add actions by having a `combatStates(currentState)` modifier
  * Combat code should use events to allow for triggers:
    * endCombatState
    * startCombatState
  * Chosen action calls executeAction(string action): {{ nextState: ?string, args: ?Array<*> }}
    * endCombatState emitted
    * if nextState should set the character's new combat state
    * startCombatState emitted (with args from executeAction return if set)

States:
* begin
* action
* choose-target
* end