bug#17439: 24.3.50; run-with-idle-timer runs on focus-out

[Juri Linkov <juri@jurta.org>]

> Why did you add focus-in as well?

When I tried to switch out with

(defun test () (message "%S" last-input-event))
(setq timer (run-with-idle-timer 0.1 t 'test))

it prints to *Messages* both lines:

(focus-in #<frame emacs@localhost 0x1121908>)
(focus-out #<frame emacs@localhost 0x1121908>)

`focus-in' is fired by the desktop window switcher
that shows the list of desktop windows to switch.
After selecting another window from the Window List,
`focus-out' is fired eventually too.

So when `focus-in' is not ignored in avoid.el then the
mouse cursor will be moved after showing the Window List.
But it seems this is not a problem because special mouse
processing is disabled when the Window List is shown.

> Wouldn't you want the mouse moved when you are about to type?

Yes, it's better to move the mouse on focusing in
than later on typing a key after switching.