issue #294 - Delete device info on ack

* blank session to kick user.
* fixed smoketest to quit on device erase.
* Using this branch since it will merge cleaner.
Merge pull request #295 from jrconlin/mozsvc/dev

issue #294 - Delete device info on ack
Merge pull request #293 from mozilla-services/extract-strings

L10n string export and import
Merge branch 'dev' into marketing