Moderately large cleanup, killing a lot of warnings.

No actual changes.
Updated the MOTD to no longer referencing DDA as a mod.
Cleared +x on source files.
Autosave fix: Seen map tiles are no longer scrambled when reloading an autosave.
Removed stub code for making shopkeepers.

Look here if reinstating it.
Removed make_all_items_owned stub.

Look here if reinstating it.
Improved garage rotation code.
Fixed chain link fence rotation.
Removed om_npcs_move, check_warmth.

If reinstating, look here.
Various whitespace fixes, look here for minor zapped stubs.