* Added "workspaces" table and associated ActiveRecord class.
* Moved ActiveRecord models from db_objects.rb into separate files.
* Do the DB migration check every time you connect (was previously done
during db_create).
* Use :dependent => :destroy associations so that we don't have to
manually delete the dependent objects.
git-svn-id: file:///home/svn/framework3/trunk@7861 4d416f70-5f16-0410-b530-b9f4589650da