Fasttracker II clone v1.44

• The second "Key Off" key (key next to left shift) didn't work on all keyboard layouts.
• Added support for importing DIGI Booster (non-Pro) modules
• Added support for importing 8-channel StarTrekker modules
• Removed calculation of some big tables because they were not really that important for performance after all, and also made the video/audio sync data more compact. Saves around ~1.8MB of RAM. Not a whole lot, but still nice.
• Code refactoring in module/sample loaders. It's easier to add new loaders now!
• Minor code cleanup and code change
• Updated help text