Etl list context

This ginormous branch modifies every database operation (where appropriate) to operate in list context with the `executemany` option or a dynamically built SQL ``WHERE IN`` clause. All code executing ``for`` loops, where each iteration was executing an HTTP or database call, was adapted to build data structures that are either sent in an single HTTP call or used to build single modified database queries that operate on a list of items. The intent is to reduce load and improve application performance.