Fixed: <rdar://problem/3937352> Quote level not maintained when copied and pasted...

	Fixed: <rdar://problem/3937352> Quote level not maintained when copied and pasted within a Mail message

        Reviewed by harrison.

        * khtml/editing/markup.cpp:
        (khtml::isMailBlockquote): new
        (khtml::createMarkup): retain the Mail quote level by including all ancestor mail block quotes
        * khtml/rendering/render_block.cpp:
        (khtml::RenderBlock::positionForCoordinates): default to downstream for the affinity since the affinity is only upstream when the cursor is clicked to the right of a wrapped line
        * khtml/rendering/render_text.cpp:
        (RenderText::positionForCoordinates): ditto

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8584 268f45cc-cd09-0410-ab3c-d52691b4dbfc