[winswitch] [ANNOUNCE] Xpra 3.0.6: mostly minor fixes, one security issue

[Antoine Martin]

Hi,

Most of these fixes are good to have but not critical, with two exceptions:
- the missing system tray bug was really hampering usability.
- the executable permissions on files uploaded is a security issue,
which could be abused to execute arbitrary commands on the server.
Updating is recommended.

Release notes:
* fix UDP with Python3
* fix key mapping issues with non-X11 clients and non-US layouts
* fix notification logging errors during shutdown
* fix window stacking order with html5 client and OR windows
* fix png/P and png/L decoding
* fix very slow startup on Debian due to missing libfakeXinerama
* fix display scaling notification warning
* fix errors generating the tray title string
* fix missing webp modules in 'clean' build target
* fix some special characters with HTML5 client
* fix initiate-moveresize with multiple clients
* fix keyboard layout detection with MS Windows 10 clients
* fix control commands argument error handling
* fix unit tests
* fix window repaint issues: system tray, Python 2 non-opengl spinners
* fix server errors during client connection cleanup
* fix spacebar and other characters with tablet input devices (mobile)
* fix unhelpful backtraces when client application windows are lost
* fix MS Windows packaging workarounds for TK
* fix for crashes on X11 displays lacking RandR support
* fix handling of non 24/32-bit png window icons
* man page connection string fixes
* disable cpuinfo module - known to cause problems on various platforms
* ignore error and continue when loading version information
* remove executable file permissions on files uploaded to the server
* blacklist 'Intel(R) UHD Graphics 620'
* use correct location for appdata.xml
* use Debian location for systemd service config file
* ensure emacs, gvim and xxdiff always use 'text' mode
* re-enable pulseaudio memfd (was wrongly disabled in v3.0.0)
* remove remnants of GTK2 dependencies from non-GTK2 components
* add missing entry to path information tool

Cheers,
Antoine