Add camera definitions for Parrot Sequioa RGB and Monochrome sensors

Renaming new flight mode to SmartRTL

This ensures no ports are being displayed to the user that are definitely unusable.

The earlier sleep calls disabled the app event queue, leading to "beachballing" in Mac OS and a visible boot delay / jitter. Running the event loop actively while waiting prevents the UI from freezing.

We were connecting to system peripherals before, which adds boot delay as QGC re-tries opening the port. We were also opening serial ports two times on Mac OS: Once as /dev/cu.usbmodem1 and once as /dev/tty.usbmodem1 - since the cu.usbmodem alias was already open, the 2nd opening always failed, leading to further boot delay.

Single firmware

Remove zip experiment.

Fixed Window landing pattern defaults override support

Code correction, Qt5.10 compatibility 

Allow custom plugins to define the use of mobile file dialog 

Fixes to CameraCalc loading plus versioning

Allow disabling the Ardupilot MAVLink dialect 

Simplify Mac package creation

Add temperature units setting

RTCMMavlink: fix sequence numbers

sequence numbers are only increased after a new RTCM message, while only
the fragment id is incremented within a fragmented message.

Update new lights step parameter setup for ArduSub

Add ArduSub 3.5.2 default params for BlueROV2

Suppress mission ack error until target_system is properly handled