* Rename EXT option to TELEMETRY
* Change test accordingly
* Rename FRSKY to TELEMETRY_FRSKY
* Rename ARDUPILOT to TELEMETRY_ARDUPILOT
* More renames (JETI, MAVLINK, NMEA)
* Fixes to make commit-test happy
* Further tests added to commit-test
* Cleanup
* Rename EXTSTD to TELEMETRY_NONE
* Allow software based volume control
- enable it for AR9X
- rename "HARDWARE_VOLUME" defines to "MASTER_VOLUME"
- adjust build-firmware.py and fwoptions.py
* Software based volume control: Do it right
* whitespace cleanup
* software volume: cleanup/revert some leftovers of undone changes