DepthAI Demo v3.0.4 - Supervisor and loading screen

In this release, we added some improvements to our Qt GUI, increasing both reliability of the script, improving UX and introducing "failsafe" mode.
The major change to the code is the new supervisor mode, enabled by default, that is responsible for setting up the environment before actually running the demo. It will also determine if Qt5 is installed on your system or if it crashes curing the runtime - if one of these occur, the demo will fallback to "failsafe" mode and use OpenCV to show the results.

Nice thing noticeable in this release is the loading procedure being now more descriptive, showing e.g. download progress, as on the image below

Full changelog

Features

• Introduce supervisor mode by @VanDavv in #573
• Add download progress indicator in Qt GUI by @VanDavv in #577

Bugs

• disable disparity encoding to prevent OOM issue by @VanDavv in #569
• Remove rectified streams detections mirroring by @VanDavv in #574
• Ubuntu 18.04 fix by @VanDavv in #571

Misc

• Increase wait time for the demo subprocess to finish by @VanDavv in #565

Full Changelog: v3.0.3...v3.0.4