Attempt to speed up the hits importer

1. Assume that @data_file describes a glob filter and so we can process more than one file at once.  This is faster than doing it a single file at a time (because we don't incur the rails environment boot time).

2. Try to poke the object into the db directly and let the db complain if the data already exists.  This makes it faster to add new data, but slows down updating existing data.  We expect to do more of the former and less of the latter, so this is ok.
Make the changes to totals_importer that we just made to hits_importer