Need to hand carry some stuff from Stable to master in order to fix

Fix crash when adding second structure scan

Signed-off-by: Willian Galvani <williangalvani@gmail.com>

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

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

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

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

Still does not support multi-vehicle

On large/high DPI screens, the whole UI scales nicely when increasing the
font size, except for the attitude widget, that was limited to 200 pixels.

Fix merge issues

save to kml use double number with 10 valid digits。

On PX4, under certain circumstances and in rare cases, there can be log
files with 0 size. In that case QGC ignored the entry and tried to
re-request the entry indefinitely.

mobile needs more testing before we can enable this.
A test on an android phone was successful however.