Add gradient support to border-image (even though it's mostly just weird).

        Reviewed by Dan

        Added fast/gradients/border-image-gradient.html
              fast/gradients/border-image-gradient-sides-and-corners.html

        * css/CSSBorderImageValue.h:
        (WebCore::CSSBorderImageValue::imageValue):
        * css/CSSStyleSelector.cpp:
        (WebCore::CSSStyleSelector::applyProperty):
        * platform/graphics/GeneratedImage.cpp:
        (WebCore::GeneratedImage::draw):
        * rendering/InlineFlowBox.cpp:
        (WebCore::InlineFlowBox::paintBoxDecorations):
        * rendering/RenderBox.cpp:
        (WebCore::RenderBox::imageChanged):
        * rendering/RenderObject.cpp:
        (WebCore::RenderObject::mustRepaintBackgroundOrBorder):
        (WebCore::RenderObject::paintBorderImage):
        (WebCore::RenderObject::paintBorder):
        (WebCore::RenderObject::updateBackgroundImages):
        (WebCore::RenderObject::arenaDelete):
        * rendering/RenderStyle.cpp:
        (WebCore::StyleCachedImage::isLoaded):
        * rendering/RenderStyle.h:
        (WebCore::StyleImage::isLoaded):
        (WebCore::BorderImage::image):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@31837 268f45cc-cd09-0410-ab3c-d52691b4dbfc