UI overhaul & code cleanup

- Use Switch views for high brightness and strobe. This gives
  bigger touch targets and a cleaner implementation.
- Move the menu into a dedicated resource instead of creating a
  submenu in code.
- Hide frequency picker when not using strobe.
- Fix logic for saving all preferences.
- Remove old strings that are not and were not needed.
- Other misc. cleanup
- Add full RTL support since we support Hebrew.
- Add GPL v3 copyright headers

Change-Id: I86a2a9415b394c7a0b0bffd1d166ee118fe4d65f