add functinoality to quest::depop()

[Robregen]

I tried using this quest::disable_spawn2 with quest::enable_spawn2.

It looks like quest::disable_spawn2 acts like a quest::depop(). it won't respawn with quest::enable_spawn2 unless the zone is reset or I use #repop command. It would be a nice feature to use since I can have it respawn at a proper time than to have to spawn too early.

EDIT: Looks like it works if I throw in $npc->Depop(1) function. then use quest::disable_spawn2 after it or on another script.