Fixed bug with Tile being deleted twice

How to reproduce:
-Start two player game with FastMode enabled
-Aquire BulletFire and SuperBullet
-Fire Bullet through explosive
-The TileHit message will now be sent twie, causing SIGABRT on the
oposing client.

Fix
-TileHit message is now only sent fro UpdateTileHit() if Tile type is
NOT Explosibe.
-Increment points is now also just called when Tile is not Explosive.
-HandleExplosions will handle incrementing of points and sending of
TIleHit if type is Explosive