Added events for various gameplay events

Added the following events for other plugins to hook into:
WarPlayerDeathEvent, WarPlayerKillEvent, WarPlayerLeaveEvent,
WarPlayerThiefEvent, WarScoreCapEvent, WarTeamWinEvent,
WarThiefDeathEvent
Properly implement War event API, some cleaning.

I changed some of the new event API code from @BenMenking to use more
Bukkit provided frameworks like Player and use basic java structures
instead of checking integers.