C1541 Tweaks
Tweaks to C1541 to support extra features.
Changes are based from: vice-emu-code-r44576-trunk-vice
- Added interleave option: https://sourceforge.net/p/vice-emu/feature-requests/470/
- When there is an image, the info command also shows: image tracks : xxx
- bpeek reports better errors when trying to read sectors with GCR errors.