DM-FORTH: FORTH implementation for the DM41X

[dmh]

I've ported FORTH to the Swissmicros DM41X hardware and added sound, graphics, file loading, keyboard shortcuts and assignment which I demonstrate in the following video.

N-Queens for an 8x8 board runs in .27 seconds on USB power which appears to be the fastest version in FORTH when reviewing the current Calculator Benchmark list.

Happy to receive feedback and suggestions for enhancements and future features. There's bound to be some bugs in it still. I'll setup a Github repository for it soon once I've done a bit of a code tidy up :-)