Local: Add Qt5-beta1 to $PATH.

See http://developer.ubuntu.com/get-started/gomobile/
Scripts: Add 'service-disable', see usage in code for instructions.
Scripts: Add 'simple-imagediff' to version control.

See usage instructions in code.
Scripts: Add 'chromium' launcher.
Scripts: Add 'kill-hanging-ssh-connections' workaround for stuck sockets.