Issue #235 NEW SUB VERSION

* Correct erase to not pre-emptively delete commands before pickup.
* Use FxA UserID instead of hash (NOTE: this will mean all previously
  registered devices will need to be re-registered.)
* Update version to indicate significant change
Move assert prints to debug log, pull uid from email

* move show assertion to debug so it shows in log
* pull the FxA uid from email if it's returned as a verified assertion
  string (this is somewhat uncommon lately)
issue #248 Upgrade userIDs from sha256 to fxa UIDs

* FxA returns a unique UID which is universal. Since we were previously
  generating a sha256 hash, transition users to the new UID. Note:
  when the wmf.counter.db.UserID.Updated hits 0 (or trends 0) over
  a significant period, this update can be safely removed.
Issue #246 - fix vet errors, simplify WS check sig

* address r? from PR 249
more r? fixes
removed extra debug line
Merge pull request #249 from jrconlin/dev

Move to FxA UIDs