ROLLBACK: Added automatic fallback to previously selected audio device

Ignore-this: 308d15c47e18dc4a5641a5d42035aa6e

darcs-hash:20130507111109-b22ec-ab03667f07adbee3c37f585f0276d4faca6b3163
Fixed re-posting notifications to avoid exceptions and make it more flexible

Ignore-this: 8187088e110e3f3b981d9cc9c6c3ea7e

darcs-hash:20130514135352-b22ec-ad5851901aa407d2c82a502a9a97ac76a109da44