M3U+ZIP handling, PET fixes

[sonninnos]

Additions:

• M3U+ZIP capabilities on par with PUAE (M3U can include zipped disks, and both can be appended/replaced via Disk Control)
  Closes Vice64x fails to autoload zipped .d64 images #136
• Drive type autodetect also when changing disks
  • Main reason for this is because the default is 1541, and thus inserting any other disk than D64 when started without content will not work. Also makes it possible to mix different types in the same M3U, even if not really practical.
  • Tapes and disks can't be mixed, but Datasette can also be enabled/disabled via Disk Control

Fixes:

• Automatic Aspect Ratio not getting the right region after model change with disabled borders, because the borderless dimension stays the same, and the geometry change was only lurking on those to change
  Closes changing model at run-time does not update automatic aspect ratio #225

• Proper PET keyboard layout needed some extra care and renovations, because different models use different layout, and the current keymap method was not flexible enough
  Closes vice_xpet wrong key layout #223

Bonus:

• PET required the data files under system/vice/PET, because the embedded data checks were goofed by VICE authors, but that is no longer the case
• Changed default PET model to 8032 just like in standalone
• Cleanups on aisle archdep

[rsn8887]

Thanks! Merging...