Implemented findWordBoundary.  We now correctly detect word boundaries.
        This function makes use of carbon unicode utilities.

        With help from hyatt, made selection correctly account for render
        continuations.  This fixes many of the 'unable to select' issues.

        Reviewed by trey and hyatt.

        * khtml/khtml_events.cpp:
        (khtml::MouseEvent::offset):
        * khtml/khtml_part.cpp:
        (findWordBoundary):
        (KHTMLPart::khtmlMousePressEvent):
        (KHTMLPart::khtmlMouseMoveEvent):
        * khtml/rendering/render_object.cpp:
        (RenderObject::checkSelectionPoint):
        * khtml/rendering/render_object.h:
        * khtml/rendering/render_text.cpp:
        (RenderText::checkSelectionPoint):
        * khtml/rendering/render_text.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@3050 268f45cc-cd09-0410-ab3c-d52691b4dbfc