Xpra

* fix error in sound cleanup code
* fix network threads accounting
* fix missing window icons
* fix client availability of remote session start feature

* fix client exit lockups on MS Windows
* fix lost clicks on some popup menus (mostly with MS Windows clients)
* fix client workarea size change detection
* fix reading of unique "machine-id" on posix
* fix window reference leak for windows we fail to manage
* fix compatibility with pillow (PIL fork)
* fix session-info window graphs jumping (smoother motion)
* fix webp loading code for non-Linux posix systems
* fix window group-leader attribute setting
* fix man page indentation
* fix variable test vs use (correctness only)
* static binary builds updates: Python 2.7.5, flac 1.3, PyOpenGL 3.1, numpy 1.7.1, webp 0.3.1, liba [] 9.7
* static binary builds switched to using pillow instead of PIL
* forward compatibility with future "xpra info" namespace changes

* fix auto-refresh: don't refresh unnecessarily
* fix wrong initial timeout when ssh takes a long time to connect
* fix client monitor/resolution size change detection
* fix attributes reported to clients when encoding overrides are used
* Gentoo ebuild uses virtual to allow one to choose pillow or PIL

* revert cursor scaling fix which broke other applications
* fix auto refresh mis-firing
* fix type (atom) of the X11 visual property we expose

* fix clipboard for *nix clients
* fix selection timestamp parsing
* fix crash due to logging code location
* fix pixel area request dimensions for lossless edges
* fix advertised tray visual property
* fix cursors are too small with some applications
* fix crash when low level debug code is enabled
* reset cursors when disabling cursor forwarding
* workaround invalid window size hints

* fix double error when loading build information (missing about dialog)
* fix and simplify build "clean" subcommand
* fix OpenGL rendering alignment for padded rowstrides case
* fix potential double error when tray initialization fails
* fix window static properties usage