Scan size selection control moved from the previewer to the scan parameters. A more logical place for it, and makes it possible to scan a preset area without having to do a preview first.

Much simplified the signal/slot communications between the scan parameters, previewer and preview image.

Kooka:
* "About" shows new home page at <a href="http://techbase.kde.org/Projects/Kooka">http://techbase.kde.org/Projects/Kooka</a>;

libkscan:
* Show previewer file size in the standard localised format, using KIO::convertSize()
* Take account of colour mode and bit depth when calculating that size
* Properly handle scanner bed size, bug 160148
* Show selection area in pixels as well as millimetres
* Fix occasional crash when using KScanOption::get() on a SANE_TYPE_STRING value