Use the clinical_trials library for interacting with the clinicaltrials.gov server to grab updated trials. Added an --update flag and started implementation of the update method, through creating XMLTrial objects from the zip file.
More work on --update. Sadly, it doesn't QUITE work yet.
Move the updating code into an updater file. Tweaked the SQLA to flush out orphan sponsors, although I don't think it's being run.
Now fetching the last changed date from the DB itself. Moved the after_flush event trigger into db.py where it should be.