Server changes

* Changed the type of damage dealt by ElectoBox. Damage to incapacitated Survivors is now dealt correctly.

* CombatTank no longer receives a health bonus for killing Survivors.

* Boss movement speed, as well as some damage, now depends on the number of players left alive, and not on their total number on the server.

* Bosses attack players more aggressively depending on the round number and the number of alive players. The more players are alive and the fewer rounds lost, the more aggressive the bosses are.

* Informational messages about killing bosses are disabled.

* Autodifficulty on the server now also depends on the rounds. The more rounds lose, the easier the bosses become.