Enable django TransactionMiddleware for everything (bug 1076949)

There is little reason to have it only for the API, it's useful
everywhere. Nested transactions should work, so we shouldn't need
to do any other modifications (hopefully).
Ask for `profile` in preverified token

Define FXA_OAUTH_URL in terms of FXA_AUTH_DOMAIN.
Replace collection data in /api/v1/search/featured/ by empty arrays (bug 1058292)

Also simplify fireplace variant now that yogafire - which doesn't care
about collections at all - is the only client left using it, and mark
/api/v2/search/featured/ as removed.
Merge pull request #2621 from diox/remove-featured

Replace collection data in /api/v1/search/featured/ by empty arrays (bug 1058292)
Merge pull request #2639 from diox/use-transaction-middleware

Enable django TransactionMiddleware for everything (bug 1076949)
Bump app-validator
Make global stats public (bug 1023645)
Expect camera permission to be 'privileged' in tests

Started failing because we bumped app-validator, and camera has been
changed to be a privileged permission in https://github.com/mozilla/app-validator/commit/180bfd095940af0a84e09f97e69616999bdccc7f
Commit from Mozilla Verbatim by user marsf.: 1984 of 1984 strings translated (0 fuzzy).
Merge pull request #2652 from mstriemer/login-from-email-1080868

Ask for `profile` in preverified token
Extract/compile script.  Today's lucky number is 6619.
fix typos in l10n
Commit from Mozilla Verbatim by user michael.koehler1@gmx.de.: 1992 of 1992 strings translated (0 fuzzy).
List priority review apps first in Tarako queue (bug 1073035)

Fixes #2661
Consolidate paginator helpers (bug 1066692)
Removed old impala_breadcrumbs
Workaround celery bug with chords and eager (bug 1083570)
Fix link to MDN in non-english locales (bug 1083580)
Commit from Mozilla Verbatim by user yfdyh000.: 1992 of 1992 strings translated (0 fuzzy).
Commit from Mozilla Verbatim by user petercpg@mail.moztw.org.: 1992 of 1992 strings translated (0 fuzzy).