40mm launcher/ammo improvements

[DyssalC]

I'm not gonna have it throw pipebombs and objects out, that's dumb and would require a weird hybrid version outside of the normal gun/ammo system. If you want that, just use the Rock-it Launcher with tomatoes or something. Any 40mm payloads will go in as shell types at some point.

Not to derail anything, but I feel these two are slightly connected: Will any of the payload ideas from the big thread of 40mm grenade shells be implemented ever? Might be a nice tag-along with this addition.