session should be logged out. Previous version (althought commented) was
closing all windows (buttons and rest are counted too), not their main
window. Thanks to some old code from babaya project I found, XmuClientWindow
is what I needed, so emulation is provided to avoid linking with libXmu.
Also added some more signals to detect quitting.
Pending issue: I'm getting strange sound driver locks when X are started
via evoke. This is un-reporoduceable when evoke is started from gui console.
This still needs to be investigate.
