Be careful with syncdb

[danfairs]

The ensure_partition command invokes syncdb directly to create its tables. This can unexpectedly sync other tables from other apps to the database if they're not already there - including those which have South migrations (as we're using Django's syncdb, not South's). We need to find some way to just sync our own models, possibly by pulling the relevant bits out of syncdb rather than just blindly running it.