From Mark Bradley:

From Mark Bradley:

- Added some error checking on record lengths being read in prior to
  their use
- Added a measure of file resync in the event of a waypoint, route or
  track being read incorrectly
- Added some conditionally compiled debug messages
- Corrected a typo in reading an altitude value
- Updated all double reads to use endian checking / changing
- Corrected a "long" known issue with routes containing single interstep links