gather: logic fix

refs #21
gather: some code cleanup

refs #21
gather: search by school/sitename as well as domain

refs #21
gather: better unknown district handling

The Unknown District (aka 'z No district found' may not always have a
dist_id of 0.

refs #21
Merge pull request #26 from orvsd/smarter_siteinfo_gather

Smarter siteinfo gather