visible == currently visible on the output it is on
(multiple workspaces can be visible at the same time)
focused == has the focus (only one workspace can be focused)
This is the foundation to use dzen2 or similar as a complete
replacement for the internal workspaces bar.
A testcase is included, more documentation about the IPC interface
will follow.
When the sending application was so fast (*cough*) that the messages
could get queued by the kernel, it may happen that we receive multiple
messages at once.
Michael Stapelberg