Revert "Skip deleted adzerk objects."

This reverts commit 1d5a6fe56d3f9f2dcee9af49abda71549dd39d4c.
update_adzerk: don't re-retrieve adzerk objects.
Don't update cfmap if it exists.
deactivate_overdelivered method for deactivating campaigns.
Method should be named deactivate_overdelivered_campaigns.