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Add GPS drivers and RTCM output for RTK GPS

Tuning not supported on VTOL

This also replaces tabs with spaces

* MavLink/master:
  Fix flight mode display for PX4. Missed reverse channel check

This does the following:
- add RTCMMavlink class that streams RTCM messages via mavlink
- add GPSProvider class that opens a serial device and uses the gps driver
  submodule to get an RTCM stream
- add a GPSManager class that manages the RTCMMavlink & GPSProvider classes
- implement gps driver callback & definitions using Qt
- add the GPSManager to the QGCToolbox

To test this, uncomment the _gpsManager->setupGPS("ttyACM0"); in
QGCToolbox.cc

Fix flight mode display for PX4. Missed reverse channel check

Restore critical messages in the main window.

Fixing transparent "Q" in all icons.

Default case for RADIO_STATUS
In response to #3151.

Version based parameter name remapping

Fix APM parameter versioning

New RCChannelMonitorControl

Fix HIL mode not being properly detected for #3226

Qstr qml v5

Missing string
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>