Needed: Battle system

[jonoxia]

Partly implemented already. Battle system needs to be highly customizable, so it should call back to userland for things such as:

• What to draw in the background
• How to decide initiative order for the round
• How to draw each monster
• How to draw stat block for each monster (if any)
• How to draw stat block for each PC
• each PC's menu of commands (possibly expressed as an override of the default set)
• AI for each monster to pick its move each round
• animation for spells and attacks in progress

[jonoxia]

TODO list:

• get/set stats methods for players and monsters
• callback to display stats for a player
• callback for individual PC to override default command set
• monsters need to have lists of actions, too
• callback for generic monster AI (e.g. "here is list of actions and targets, return action and target monster chooses")
• callback for specific monster to override generic AI with their own AI.
• callback to decide order of actions in round ("sort these guys in initiative order please")
• callback for start-battle animation
• function to remove dead monster/PC from combat turn, end battle when one side is wiped out
• correctly handle "random_enemy" target type -- (allow callback for random enemy selection)
• correctly handle "all_enemies" and "all_allies" target types
• function to pass a "battle effect message" (e.g. target.takeEffect("damage",{amount: 5, type: "fire"}); )
• callback for default "battle effect message" handlers (e.g. battleSystem.onEffect("damage", function(target, data) { target.modifyStat("hp", (-1) * data.amount);} ); )
• callback for specific monsters/PCs to override default with their own "battle effect message" handlers

[jonoxia]

I think the battle system is now done enough to close this bug. I will open smaller bugs for the remaining desired features.