Mouse focus issues

[Rob Foehl]

I've been playing with the multiwindow stuff (in the test 73 build), and
I've run into a problem.. I use mouse focus under win32 (the "Activation
follows mouse" option in tweakui), and my xterms are misbehaving.. each
time a new window is spawned from one (for example, run notepad from an
xterm), if the xterm loses focus, it spews newlines into the terminal..

The problem becomes particularly apparent in xev.. hold down enter and
move the mouse out of the window, you get a stream of KeyPress/KeyRelease
and then a LeaveNotify as expected.. do it again with mouse focus enabled,
and the keypress/release events keep coming, despite the window losing
focus...

I haven't tested this in other modes (rootless, etc), but I'm fairly sure
that'd be pointless anyway... just my guess, though.

-Rob