Added two options, one which lets user choose which gamepad to use, and one
which allows game to be played with gamepad while in the background.
These two features together allow for "splitscreen" (sort of) multiplayer by
starting up instances and joining them together and selecting different
gamepads for each one.
Gamepad choices are 0-7. If a number is chosen that does not correspond to a
gamepad, the previous gamepad (last number you were on this session that had
a working gamepad) is used.
Red Coins will now properly play the cutscene for who collected the last red coin.
Secrets will now properly play the cutscene for who collected the last secret.
Treasure Chests will now only play the star cutscene for the person who opened the last chest.
Properly named some unknown Treasure Chest fields.
The Chain Chomp Chain should now properly be despawned for late joiners.
Improved the Big Boo's Haunt Merry-Go-Round checks for Mario.
convert_functions.py no longer hardcodes acceptable LOT_ values
Added characters.h and surface_collision.h to convert_structs.py
Prevented mod filenames with a slash in it from being considered acceptable
Sanitized mod filenames when received from the server
