====== PvM arena idea ======

Glacirius brought suggestion about PvM arena

  * We can use mobs already on server. IDK if plain as they are on server or slightly tuned..
  * mobs shouldn't destroy things like mesecon button, torches (or another light blocks), maybe also obsidian glass
  * mobs should drop some special item (coin, badge, something like that) which will be tradeable for some special items in server shop
  * we can transform zombie into "Notch" mob which will be dropping cups of coffee (it can be stronger than zombie maybe) (Zel maybe can do skin)
  * In arena will be button (or more buttons to spawn certain mob/mob combination) (button must be protected to not spawn enormous count of mods when someone will be pressing it frenetically)