[wmii] No-bars patch

Hello there!

People seemed to be interested in a no-bars patch, so I hacked
something up. You can disable framebars via /ctl (framebars 0|1), and
disable the bar with the -b option given to wmiiwm. At least the bar
part is implemented pretty crappily, and wmii would need some more
refactoring and added features to have this feature in somewhat clean
code. (I suppose more EWMH.) Whatever. Enjoy it!

Denis