This allows to configure / override what gets considered to be the "focused screen". Ref: https://awesome.naquadah.org/bugs/index.php?do=details&task_id=1029 Closes https://github.com/awesomeWM/awesome/pull/94.
This simplifies the logic a bit since all of the fg/bg colors are always set when it gets to checking the client state.
Signed-off-b: Julian Wollrath <jwollrath@web.de>