Add support for versioned db + update db with latest changes

[fordfrog]

with columns and tables being added, database structure must be versioned and updated when version is older than the version of the app

[fordfrog]

there is an update script for postgresql in the 1.6.0 release but complete update mechanism is not in place yet

[asgeirrr]

Hi, can I ask what is the status on this? I am using your ulitity since it works better than the official set of Python scripts but incremental updates would be quite handy, it's a huge database...