Narrow KeyboardInterrupt handling
load-datasets: factor out common code
start of portal-update command
increase changed_packages_activity_list_since limit
factor out and document worker pool code
factor out job assignment
work on portal-update command, better docstrings
work on portal-update-worker command
portal-update-worker command retrieve packages
portal-update-worker command: create and unchanged working
portal-update-worker command: delete working
portal-update-worker command: update working
factor out getting site user
portal-update: catch KeyboardInterrupt
_changed_package_ids_since: fix seen_id_set usage
Merge pull request #92 from wardi/master

Add portal-update command and factor out worker process management code