the preview widget

[Casper Boemann]

Hi

As you might have noticed I have changed the layout of the preview, to look 
more like digikam.

Now the preview widget itself also needs some updating:
 - zoom doesn't exist in the digikam preview - the image is zoomed all out
 - that doesn't mean we shouldn't keep the abillity to zoom, but I think 
default should be zoomed out as in digikam.
 - the update of the preview seems slow. Is the algorithm as effective as it 
can be?

This is not something I'm going to do, but I think we should discuss it and 
put it in the TODO.

-- 
best regards / venlig hilsen
Casper Boemann