Extract the iuse function to place monsters into an iuse_actor class

Because more robots means more fun.

New iuse_actor class is `place_monster_iuse`, it allows to place any kind of monster (only needs the monster type id).

This replaces `iuse::manhack`, `iuse::turret`, `iuse::turret_laser` and `iuse::turret_riffle`.

Optional messages for friendly / hostile monsters can be specified, too.

I'd like to extend this to secubots because I recently "befriended" one in a prison. But it's of no use there, shutting it down an disassembling it seems rewarding. Or I could take the secubot item with me and place it again it defend my fortress of solitude.