Chaingun should also give the player a machinegun

[Braden Obrzut]

http://www.doomworld.com/vb/showthread.php?s=&postid=1135263#post1135263

Most likely an assumption on id's part, but could lead to game play differences. The chaingun should give the player a machinegun if they don't have one already.

[Braden Obrzut]

Fixed in changeset 4ed8931.