Update/re-engineer the rake setup task

The rake setup task hasn't been updated since who knows when.

The setup task should do the following operations:

• Init git submodules
• Update git submodules
• Ask if you want a SQLite database for development
  • if so, setup the appropriate database.yml file
• Load the database schema
• Add the standard user roles
• Add the standard settings
• Create one article, one news item, one event, and one gallery
• Create the first administrator according to user input

I don't think we really need the populate task any more, at least once we have resolved this ticket.