Xpra

* fix xpra upgrade
* fix xpra control error handling
* fix window refresh on inactive workspace
* fix slow cursor updates
* fix error in rgb strict mode
* add missing x11 server type information

* fix painting of forwarded tray
* fix initial window workspace
* fix launcher with debug option in config file
* fix compilation of x265 encoder
* fix infinite recursion in cython csc module
* don't include sound utilities when building without sound

* honour lossless encodings
* fix avcodec2 build for Debian jessie and sid
* fix pam authentication module
* fix proxy server launched without a display
* fix xpra info data format (wrong prefix)
* fix transparency with png/L mode
* fix loss of transparency when toggling OpenGL
* fix re-stride code for compatibility with ancient clients
* fix timer reference leak causing some warnings

* Python3 / GTK3 client support
* NVENC module included in binary builds
* support for enhanced dummy driver with DPI option
* better build system with features auto-detection
* removed unsupported CUDA csc module
* improved buffer support
* faster webp encoder
* improved automatic encoding selection
* support running MS Windows installer under wine
* support for window opacity forwarding
* fix password mode in launcher
* edge resistance for automatic image downscaling
* increased default memory allocation of the dummy driver
* more detailed version information and tools
* stricter handling of server supplied values

* fix invalid pixel buffer size causing encoding failures
* fix auto-refresh infinite loop, and honour refresh quality
* fix sound sink with older versions of GStreamer plugins
* fix Qt applications crashes caused by a newline in xsettings..
* fix error with graphics drivers only supporting OpenGL 2.x only
* fix OpenGL crash on OSX with the Intel driver (now blacklisted)
* fix global menu entry text on OSX
* fix error in cairo backing cleanup
* fix RGB pixel data buffer size (re-stride as needed)
* avoid buggy swscale 2.1.0 on Ubuntu

* fix error when clients supply invalid screen dimensions
* fix MS Windows build without ffmpeg
* fix cairo backing alternative
* fix keyboard and sound test tools initialization and cleanup
* fix gcc version test used for enabling sanitizer build options
* fix exception handling in client when called from the launcher
* fix liba [] dependencies for Debian and Ubuntu builds