Add mob target changing

Add mob corpses. Corpse can be open like backpack on ground. Player can't throw corpse or put items inside. Also coprses don't dissapear after browse field. Corpse have 2 stages - normal and bones. Stage is changed after 5 min. While in first stage, corpse can be skinned.

Add Annihilator quest

Add blessed wooden stake quest

Fix levitate spell - now its unable to levitate on barriers

Remove "press F to browse field" communicat while r-click ground

Update resource pack