This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
also add a hard limit of 1000 users per job run so we do not clog the
scheduler
destroyer.destroy has a transaction and this can have some serious complications
with the open record set find_each has going
* Remove use of 0 in favor of `TrustLevel.levels[:newuser]`.
* Consolidate two tests into a single one.
* Test that disabling the feature works.
* Avoid loading full ActiveRecord object in test when we only need to
know the existence of the record.
