Xpra

* fix "xpra info" with bencoder
* ensure we re-sanitize window size hints when they change
* workaround applications with nonsensical size hints (ie: handbrake)
* fix 32-bit painting with GTK pixbuf loader (when PIL is not installed or disabled)
* fix system tray forwarding geometry issues
* fix workspace restore
* fix compilation warning
* remove spurious cursor warnings

* fix NVENC GPU memory leak
* fix video compatibility with ancient clients
* fix vpx decoding in ffmpeg decoders
* fix transparent system tray image with RGB encoding
* fix client crashes with system tray forwarding
* fix webp codec loader error handler

* fix compatibility with ancient versions of GTK
* fix crashes with malformed socket names
* fix server builds without client modules
* honour mdns flag set in config file
* blacklist VMware OpenGL driver which causes client crashes
* ensure all "control" subcommands run in UI thread

* fix Cython 0.20 compatibility
* fix OpenGL pixel upload alignment code
* fix xpra command line help page tokens
* fix compatibility with old versions of the python glib library

* fix compatibility with old/unsupported servers
* fix shadow mode
* fix paint issue with transparent tooltips on OSX and MS Windows
* fix pixel format typo in OpenGL logging

* NVENC hardware h264 encoding acceleration
* OpenCL and CUDA colourspace conversion acceleration
* proxy server mode for serving multiple sessions through one port
* support for sharing a TCP port with a web server
* server control command for modifying settings at runtime
* server exit command, which leaves Xvfb running
* publish session via mDNS
* faster OSX shadow server
* OSX client two-way clipboard support
* OSX keyboard improvements, swap command and control keys
* support for transparency with OpenGL window rendering
* support for transparency with 8-bit PNG modes
* support for more authentication mechanisms
* support remote shadow start via ssh
* support faster lz4 compression
* faster bencoder, rewritten in Cython
* builtin fallback colourspace conversion module
* real time frame latency graphs
* improved system tray forwarding support and native integration
* removed most of the Cython/C code duplication
* stricter and safer value parsing
* more detailed status information via UI and "xpra info"
* experimental HTML5 client
* drop non xpra clients with a more friendly response
* handle non-ASCII characters in output on MS Windows
* libvpx 1.3 and ffmpeg 2.1.3 for OSX, MS Windows and static builds