Forgot to import freenasOS.Package as Package
Logic error:  when doing a delta-update, it was not noticing
that it found the delta package file.
Do not assume AvailableTrains returns something
Make sure system_dataset_path exists
Fix train to download
Current train should not tell user selected value but actual current train
Inverted old and new packages in the update datagrid
Fix link target for /var/db/samba4.

Ticket:	#6284
Merge remote-tracking branch 'origin/master' into freebsd10