Fix NPE when players join a team.
Players now load on server startup

Similar to how teams are loaded.
Fixed some flatfile issues for /pb team info.
Added Match Commands

/pb match start [Team1] [Team2]
/pb match stop

Config Option for Minimum Team Size
Starting WorldGuard Support
(WorldGuard) Players can't enter field

If a match is going on, and the player's team isn't in it, they will not
be allowed to enter the field.
(WorldGuard) Players can't build on field.

Configurable. In order to allow Bending on the field, the region flag
must allow the player to build. This will override that, allowing them
to Bend, but not build.

Players with probending.worldguard.buildonfield will be able to bypass
this check and build regardless.
Oops

Forgot to add BlockPlaceEvent ;p
Automate Probending Matches

(Relies on WorldGuard and defined Zones.)