Don't show deck upgrade wizard on AnkiDroid version upgrade.

The upgrade wizard will stlil appear on any startup if you have no collection.anki2 file and at least one old .anki file in the AnkiDroid directory. There is also a menu option to manually trigger the wizard.
Add automatic database check on version upgrade.
Merge pull request #92 from hssm/v2.0.2-dev-dbcheck-on-upgrade

On upgrade, do a DB check and don't show upgrade wizard