Small improvements and fixes. Hopefully basic Ubuntu 22.04-LTS compatibility.

General:

• GetClicks(): Add timeout for 1st click, and click time reporting.
• Setup/Download/UpdatePsychtoolbox(): Add highly experimental optional support for non-interactive operation. May help sysadmins to setup multiple machines faster without too much user interaction. Experimental, unsupported in case of trouble, will not work easily on Linux - would need more work to update PsychLinuxConfiguration.
• PsychPaidSupportAndServices(): Update language a bit for new support conditions.
• Fixes by Diederick for DrawFormattedText2() cached text drawing while geometric transformations are applied.
• DKLDemo.m: Some comment fixes by David Brainard.

Linux:

• PsychPortAudio(): Change realtime priority setup for ALSA and Pulseaudio: Instead of assigning static FIFO RT priority 1, use priority of main thread (aka Priority()) + 4, so audio processing stays at higher RT priority than main thread or other PTB threads. May help some special edge cases, e.g., Microsoft Surface Pro 6 audio glitches in some scnearios that I could not reproduce, but a user could. See https://psychtoolbox.discourse.group/t/audio-and-surface-pen-questions/4276
• Add a GitHub actions CI setup to allow to build our mex files for 64-Bit Linux on Intel in the GitHub cloud, both for Octave 5.2 and Matlab under Ubuntu 20.04-LTS.
• Make Screen() mex files hopefully compatible with Ubuntu 22.04.0-LTS, by changing link dependency to libdc1394-25. Only lightly tested.

Windows:

• Require use of GStreamer 1.18.x series, 1.18.5 as latest tested release. GStreamer 1.20 contains multiple potential compatibility bugs wrt. fontconfig / high quality text rendering under Matlab + Windows. Octave 6.4 + Windows should be unaffected, as are other operating systems.