input.

to reproduce, do the following:
1. open shortcuts configuration and assign the shortcut "a" to the about
dialogue.
2. activate default tool => a shows about dialogue
3. create textshape and write something with a => about dialogue shows,
but it shouldn't

In the qt lib textinputs are working, while there are these shortcuts,
so in flake it should also work.

the patch works this way:
the canvas forwards bool QWidget::event(QEvent* theEvent) to
KoToolProxy. The tool proxy asks the current tool, if it is in text mode
(isInTextMode) and interrupts the shortcut if so.

svn path=/trunk/koffice/; revision=1182228