Deleted Version.java and VersionTest.java

These were being used in several projects, so I moved them to their only
project. So that any changes to Version.jar would propagate to all
depending projects.
Added Version.jar compile time dependency.

It is not necessary to have Version.jar during runtime because its classes
are shaded into BombArena.jar during compile time (using the
maven-shade-plugin).
Refactored to use the new Version library.
Refactored to use the new Version library.
Fixed ItemSpawnEvent and ItemDespawnEvent.

// This annotation broke all events:
@ArenaEventHandler
public void onItemSpawn()

// This annotation fixed the events:
@ArenaEventHandler (needsPlayer=false)
public void onItemSpawn()

To-Do:
-Will probably get the bombID from the ItemSpawnEvent and use that to track
the bomb. At the very least, I can use the bombID to know whether or not
to cancel the ItemDespawnEvent.

-Might move the hologram code from MatchStartEvent to ItemSpawnEvent.

Delete all references and uses of matchID:
-Since BattleArena creates a new instance of BombArena for each one
configured on the server, there is no need to use the matchID.