positioned blocks inside centered tables inside enclosing tables
	with percentage widths work correctly.

	This fix also causes the textfields on mrskin.com to show up
	again.

        * khtml/rendering/render_box.cpp:
        (RenderBox::RenderBox):
        (RenderBox::setPos):
        * khtml/rendering/render_box.h:
        * khtml/rendering/render_container.cpp:
        (RenderContainer::addChild):
        * khtml/rendering/render_layer.cpp:
        (RenderLayer::constructZTree):
        * khtml/rendering/render_object.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@2047 268f45cc-cd09-0410-ab3c-d52691b4dbfc