Revert "Added map categories for most mountable games"

This reverts commit a38a4afe2bf09a57633cbe3aed014175be7d57ac.
Added map categories for most mountable games

Zeno clash and Left 4 Dead 1 are not added, since I don't have them.
Alien Swarm and Left 4 Dead 2 are added, even though they aren't
mountable. Added ability to specify single maps for categories.