* Use schedulers with ChainedPromise
* Add full queue initializer redirection in Schedulers
* pass scheduler to OWSURLSession
* Use schedulers in SystemStoryManager
* make SystemStoryManagerTest synchronous
This change should have no user impact.
Two changes:
1. Calling `advance(to: timeInThePast)` is now a fatal error.
2. Calling `advance(to: currentTime)` is now tested.
* Add ability to compute registration recovery password
* Add RegistrationCoordinator
* remove repeat nav controller that evan added
* Scaffolding for RegistrationCoodinator test
* Add first round of RegistrationCoordinator tests, some stuff I needed to get them working, and some fixes to RegistrationCoordinator itself I discovered thanks to the tests
* switch to owsFailBeta
* Add auth credential candidate flow tests, related fixes and additions to coordinator and friends
* Add tests for session based registration path and associated fixes
* PR comment nits