bug#16382: Cut/Copy tool-bar icons issue

[Stefan Monnier]

>> I notice that when I select some text in the scratch buffer with the mouse
>> the tool-bar icons for "cut" and "copy" remain grayed, i.e. not active and
>> I cannot cut or copy the selected text clicking those icons, but the keys
>> combination, C-w and M-w work as expected.
>> 
>> This occurs with recent trunk with my GTK builds on Cygwin and
>> GNU/Linux Kubuntu 12.04.

Indeed, the toolbar needs to be re-computed, and nothing causes it so
far (it might have worked earlier as a side-effect of something else,
but with the more refined choice of what to redisplay this doesn't
happen any more).

I've installed a patch which calls force-mode-line-update when the mark
is (de)activated.


        Stefan