Fixes a bug that prevents killing AIs before roundstart
Adds the ability to spawn dead AIs, dead facehuggers and dead slimes on away mission maps. Expands on dead human spawning.
Fixes bugs that prevent spawning dead slimes and dead monkeys before roundstart.
Hopefully fixes Giacom's complaints
Removes unneeded code as pointed out by Cheridan. Thanks for the help.
Merge pull request #2336 from Tenebrosity/deadmonkeyslimespawn

Fixes map corpse spawn bugs and expands on spawning corpses on the map