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

Moved "Grid Lines" out of General Options and into the Video Stream Widget
Made a QGC custom Switch element

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

This reverts commit 52160d80.

- Added menu options to select new mode as well as new settings and defaults

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

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

Just use settings defaults