MEDIA: Forgot to remove the (a|b) in certain post-fixes models.

This will fix the certain holes while in game.
But not on both machines I tested on. Hope you'll be lucky!
Fixed most of the material files, keeping the link to the general.material file.

Note: The Orc and Kobold material files links with their meshes is broken somehow.
Made the overall world lighting slightly brighter to be less eye-hurting.

Previously, it was so dark, I had problems seeing creatures
on my desktop, even with standard brightness.
Fixed the coloring of the tiles when claimed.

This raised another bug:
- When room tiles are drawn over a claimed tile, their color
can be seen through the room tile ground.
In that case, the tile under it should be removed.
Fixed the keyboard move up/down behaviour.