Xpra

* fix crash with unknown X11 keysyms
* avoid error with focus being given to a destroyed window
* honour window aspect ratio

* fix version string hiding ssh password prompt
* fix focus handling for applications setting `XWMHints.input` to False (ie: Java)
* fix ssh shared connection mode: do not kill it on Ctrl-C
* fix sanitization of aspect ratio hints
* fix undefined variable exception in window setup/cleanup code
* fix undefined variable exception in window damage code
* fix dimensions used for calculating the optimal picture encoding
* reduce Xdummy memory usage by limiting to lower maximum resolutions

* fix division by zero in graphs causing displayed information to stall
* fix multiple tray shown when using the launcher and password authentication fails
* fix override redirect windows cleanup code
* fix keyboard mapping for AltGr with old versions of X11 server
* fix for Mac OSX zero keycode (letter 'a')
* fix for invalid modifiers: try harder to apply valid mappings
* fix gtk import warning with text clients (xpra version, xpra info)

* Mac DMG client download
* Android APK download
* fix "AltGr" key handling with MS Windows clients (and others)
* fix crash with x264 encoding
* fix crash with fast disappearing tooltip windows
* avoid storing password in a file when using the launcher (except on MS Windows)
* many latency fixes and improvements: lower latency, better line congestion handling, etc
* lower client latency: decompress pictures in a dedicated thread (including rgb24+zlib)
* better launcher command feedback
* better automatic compression heuristics
* support for Xdummy on platforms with only a suid binary installed
* support for 'webp' lossy picture encoding (better and faster than jpeg)
* support fixed picture quality with x264, webp and jpeg (via command line and tray menu)
* support for multiple "start-child" options in config files or command line
* more reliable auto-refresh
* performance optimizations: caching results, avoid unnecessary video encoder re-initialization
* faster re-connection (skip keyboard re-configuration)
* better isolation of the virtual display process and child processes
* show performance statistics graphs on session info dialog (click to save)
* start with compression enabled, even for initial packet
* show more version and client information in logs and via "xpra info"
* client launcher improvements: prevent logging conflict, add version info
* large source layout cleanup, compilation warnings fixed

* fix bencoder to properly handle dicts with non-string keys
* fix swscale bug with windows that are too small by switch encoding
* fix locking of video encoder resizing leading to missing video frames
* fix crash with compression turned off: fix unicode encoding
* fix lack of locking sometimes causing errors with "xpra info"
* fix password file handling: exceptions and ignore carriage returns
* prevent races during setup and cleanup of network connections
* take shortcut if there is nothing to send

* fix memory leak in server after client disconnection
* fix launcher: clear socket timeout once connected and add missing options
* fix potential bug in network code (prevent disconnection)
* enable auto-refresh by default since we now use a lossy encoder by default