- Fixed a bug which would cause the UDS index to be perceived as corrupt
  when a VDO volume is moved to a system with a different endianness.
- Modified UDS index rebuild to be interruptible so that shutting down a
  VDO whose index is rebuilding need not wait for the index rebuild to
  complete.
- Prevented two VDO devices from being started on the same storage.
- Fixed rare races which could result in VDO issuing I/O while suspended.
- Fixed crashes when re-suspending a VDO after it had been resumed.
- Made async mode ACID. Added async-unsafe mode to preserve the performance
  of the old implementation.