When a file is finished in VOSpace, the value of the 'done property' is now 
the operator's username (instead of just a static flag value).
By default the VOSpace progress manager will no longer record partial
progress in a file.
Added sync_enabled flag to SyncingVOFile constructor.  The application
now has syncing turned off, meaning the user must manually copy their
results to VOSpace after finishing.
The application now has the notion of separate input and output 
contexts.  Added -o/--output option to validate.py so that you can change
where output files get written.