[#29][Target Devices] Resolve "Update Preference to allow targeting to devices"
requested to merge 29-preferences-page-edit-preference-to-allow-targeting-live-notifications into master
- Updated AddPreference page to allow selection of target devices
- Updated ListPreference page to show currnet enabled target types
- Polished AddDevice for better user experience and better error handling
- Added Edit device (name and info) feature
Closes #29 (closed)