Add missing copyright.
If the cache hit fails create a new objects instead of doing a lookup to find
if the objects exists and then create it. This is alot less safe, since it
removes a bunch of constraints, but it should be okay if the database is empty
when running this script.

This makes the script run a lot faster :)
If a sideeffect exists in the frequency table but not in the sideeffects table
create it with the name from the frequency table.

If a drug exists in the frequency table but not in the sideffects table create
it with the name "unknown drug %d"
Remove superfluous fields.
Add __unicode__ methods for two models.
Oops, forgot to call .save()