Attached patch fixes some issues in the floppy disk controller:
- Enhance reset support (external and software)
- Use MAX_FD constant when possible
- Support up to 4 drives if MAX_FD is set to 4
- Fix DOR register, which should be writable at any time
- Let MSR return 0x20 when non-DMA transfer is happening
- Don't assume caller wants to read whole track at once
- Add seek to next sector when in non-DMA mode
- Fix non-DMA write, which was stopping after only 1 byte

Credits to Stuart Brady to help me to debug some issues...

Changelog v1 to v2:
- Fix non-DMA write, which was stopping after only 1 byte
Changelog v2 to v3:
- Update to current CVS

Programs can now be started from the floppy

To Blue Swirl, I don't forget the floppy problem with SPARC.