* C128: add support for .d71 and .g71 disk images
* C128: add creating or resizing tracks in .g64/.g71 images
* C128: change "1571" flag from bit 8 of lba to bit 10
* C128: fix second side of d71 images
* C128: small fix for gcr track end position detection
* C128: set track speed to 8 for MFM tracks
* C128: provide detected disk image type to core
* C128: add bit to indicate disk image GCR support