- KPDFPage: added a method to retrieve the text that is inside a rect from
    the embedded TextPage.
- PageWidget: (GFX) added methods to set the 1st (placed on click) and 2nd
    (placed on drag) corners of the selection area.
- PageView: A) set first corner on click, B) second on moves, C) retrieve
    text inside the rectangle on release.

svn path=/branches/kpdf_experiments/kdegraphics/kpdf/; revision=352751