Bug 1069412 - Email constantly asks me to reauthenticate
Add tests using fake oauth server, corrects loop bug

Most of the OAuth fake-server changes happened in mail-fakeservers on:
https://github.com/mozilla-b2g/mail-fakeservers/pull/22
which I've speculatively landed and released as v0.0.28.  Further rev's
can be done as needed.
Merge pull request #341 from jrburke/bug1069412-email-xoauth2-reauth

Bug 1069412 - Email constantly asks me to reauthenticate r=asuth