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.
Reorganized the file a bit.
Added ability to specify single maps for categories.

Oh and by the way, is matNoIcon even used?
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.
Merge pull request #12 from robotboy655/master

Added map categories for most mountable games