up to 0.10.11 (2014-01-07)

- fix popup windows focus issue
- fix "xpra upgrade" subcommand
- fix server backtrace in error handler
- restore server target information in tray tooltip
- fix bencoder error with no-windows switch (missing encoding)
- add support for RGBX pixel format required by some clients
- avoid ffmpeg "data is not aligned" warning on client
- ensure x264 encoding is supported on MS Windows shadow servers