Scores now saved to disk and IBM PCjr support

The number of times each level was beat and the maximum distance traveled in the endless level is now saved to disk, and this information is displayed in the level selection screen.

The game now also runs rather well on the IBM PCjr and is also available as a cartridge ROM.

Detailed changelog:

• Scores now saved to disk (STELLAR.SCO)
• Normal levels: Display the number of times each level was beaten in the level list.
• Endless level: Display the best distance in the level list.
• The Tandy sound option (/TANDY) should now work in the VGA version too.
• Improved PCjr support: Checks if there is enough memory, check if the program is loaded in fast memory (above 128k) and relocate if necessary.
• Fix snow when updating the palette on PCjr.
• PCjr Cartridge version of the game (Binary ROM file and .JRC file)
• Command-line arguments are now case-insensitive.
• Add a command-line option to set the language to French (/FR)