Vexos basic updated

I've been able to spend some time on VexOS and VexosBASIC again.

As a result, i managed to resolve the musicplayer issues, but i still have troubles finding a proper packing routine for the songs. Songs are generally 50-100kb in size, and need to be compressed to ideally about 16kb or less. Current packing methods (i tried 3 different methods so far) give me about 20-40kb for each song, making a lot of songs unsuitable for the vectrex (with about a 24kb limit for data).

As for VexosBASIC, i've been able to do a bunch of updates, these include:
- RECT and CIRCLE draw functions
- DRAWSHAPE function to draw vexosbasic shapedata (which can be exported by vectorpaint)
- DRAWBITMAP function
- CHECKCOLLISION function
- Handling of DATA segments
- Various small fixes

With these last updates, everyone should be able to make proper games for it. In theory you should be able to create almost every type of game you like now.

VexosBasic is now open for people willing to beta-test.
And if you create something nice with it, i will feature it on the upcoming vexosbasic website.