* Added support for sat count to Sensors check control

* QGCCheckListItem -> PreFlightCheckButton
* CheckList -> PreFlightCheckList

Automated preflight checklist: Initial commit. Note that this requires an autopilot firmware that writes the respective health flags in the SYS_STATUS mavlink message

Signed-off-by: Patrick J.P <patrickelectric@gmail.com>

Allow plugins to define a left placement for its custom flight widget.
When placed on the left, the action tool strip is placed on the right side.

- popup don't work with map
- improve popup visible logic
Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

For whatever reason, showing the dialog through a function causes a crash in QML (undebugable--new word!)

Internet available now has a signal

- Don't allow goto click while other guided ui is visible
- Use NoMouseThroughRectangle for guided ui popups
- Better visuals for goto indicator in map

Adding mux GStreamer plugin libraries to Android (to enable video recording on Android)
Adding an option to limit the amount to disk used for saving videos
Adding an option to show/hide the REC button (allowing plugins to handle the recording in their own way)
Adding simple frame grab to file

- Altitude slider not showing up
- Continue mission not showing up in action list