Win Conditions, SpawnProtection

Added Win Condition by getting a specified amount of kills. Changable by
dm_maxkills (default: 30). A little further team support.

Added Spawn Protection. When a player spawns he is set to invulnerable
for a certain amount of time after spawning. Change the value in seconds
by changing dm_spawnprotectionDur (default: 3).

Deleted weapon.lua. What was that anyway, was empty?