http://bugs.webkit.org/show_bug.cgi?id=15954
        Move DOM Selection operations out of SelectionController

        No change in functionality.

WebCore:
        * editing/SelectionController.cpp:
        (WebCore::SelectionController::setSelectedRange):
        * editing/SelectionController.h:
        * page/DOMSelection.cpp:
        (WebCore::DOMSelection::anchorNode):
        (WebCore::DOMSelection::baseNode):
        (WebCore::DOMSelection::anchorOffset):
        (WebCore::DOMSelection::baseOffset):
        (WebCore::DOMSelection::focusNode):
        (WebCore::DOMSelection::extentNode):
        (WebCore::DOMSelection::focusOffset):
        (WebCore::DOMSelection::extentOffset):
        (WebCore::DOMSelection::isCollapsed):
        (WebCore::DOMSelection::type):
        (WebCore::DOMSelection::rangeCount):
        (WebCore::DOMSelection::collapse):
        (WebCore::DOMSelection::collapseToEnd):
        (WebCore::DOMSelection::collapseToStart):
        (WebCore::DO...