Version consistency check

See issue #592.

This codepath is hit only:
* During registration
* During syncing
* During zip-file creation
Other changes were made to remove version information where it was redundant (i.e. already contained as the default)

All references to version.VERSION have been replated with Device.get_version(), which ensures a version consistency check.  

In the future, as the update procedure matures, we can make sure to force this update to occur as well.

Testing:
* Tested both registration and syncing.

@jamalex, this is in your domain again--please take a look!