v0.5

Release Notes:

• USB: Overhaul the protocol and allow writes to be terminated at index
  • Terminate-at-index is always used by current Python control script
  • Terminate-at-index prevents an over-long write from overwriting itself
  • Fix interruption of track writes (eg. KeyboardInterrupt)
• gw.py: New option --adjust-speed to normalise flux times for target drive
  • Measures RPM of the target drive and calculates an adjustment factor