No bug - Import current Fennec files.
Bug 970176 - Pre: import LocaleManager.java into the repo.
Bug 970176 - Pre: add stub BrowserLocaleManager.
Bug 970176 - Part 1: add LocaleAwareActivity.
Bug 970176 - Part 2: prepare locale in Product Announcements.
Bug 970176 - Part 3: prepare locale in Health Report document generation.
Bug 970176 - Part 4: make FxA accounts locale-aware.
Bug 970176 - Part 5: prepare locale prior to showing a sent tab notification.
Bug 970176 - Part 6: make Send Tab activity locale-aware.
Bug 970176 - Invoke LocaleManager locale switching code prior to handling strings or Locale in background services. r=nalexander