Change to kill unit spell and delete unit map editor button mechanic

[makazuwr32]

In aof we have number of units who drop weakened version of self on "death" — hydra for example.
There also are plans to add units which will drop on "death" more powerful self version instead.

So i want to change these 2 — kill spell and delete unit in map editor — from simple insta-death effect to erase — unit just erased from the game without any drop on death or any effect triggered on its death.

Also i want to ask to add such trigger effect to map editor so we would be able to erase unit without dropping corpse or weakened version.