South Database migrations for RockStor

Add south to settings.conf.in and setup.py so that South is installed
and added to INSTALLED_APPS.
Modify datastore and smartdb so that they contain the initial set of
tables for existing models (at the time of conversion), as well as the
south_migrationhistory table (when the app is converted to use south, it
fakes the initial migration, ie adds an entry to this table to show that
the app has been migrated to 0001).
Add migrations dir with initial migrations to storageadmin and
smart_manager.
Modify prep_db to check for the existence of data before creating it.
Modify buildout so that it
1. doesnt remove the databases.
2. runs migrations.
3. restarts servers.
Corrected errors in buildout.cfg

Corrected the command in restart-servers
Removed the commented clean-check section
Merge branch 'issue#28_db_migrations' of git://github.com/sujeetsr/rockstor-core into sujeetsr-issue#28_db_migrations
Buildout modifications for database migrations

Add datastore.in and smartdb.in as templates to be copied if no database
exists.
Add stop-servers to shutdown servers.
Add clean-check section - if either datastore or smartdb don't exist,
assume its a fresh deploy, and copy the database files from the conf
dir.
Add db-migrate section to run migrations
In prep_db, check for existence of objects in a better way.
Move extra-stuff before collectstatic because collectstatic fails if the
log dir is not present
Merge branch 'issue#28_db_migrations' of git://github.com/sujeetsr/rockstor-core into sujeetsr-issue#28_db_migrations