Fixed wrong usage of QStyleOptionViewItem: caching of the file item in the constructo...

Fixed wrong usage of QStyleOptionViewItem: caching of the file item in the constructor is too early (thanks to Fredrik for the hint!). This fixes 2 issues:

* the selection color of the details view now uses the correct selection color
* changing the colors of KDE results in updating the colors of all Dolphin views

CCMAIL: hein@kde.org
CCMAIL: ereslibre@kde.org
CCMAIL: mw_triad@users.sourceforge.net

svn path=/trunk/KDE/kdebase/apps/; revision=745700