Simplify the Render(screen, document) function.

examples/dom/border.cpp

examples/dom/dbox.cpp

examples/dom/gauge.cpp

examples/dom/graph.cpp

examples/dom/hflow.cpp

examples/dom/html_like.cpp

examples/dom/package_manager.cpp

examples/dom/paragraph.cpp

examples/dom/separator.cpp

examples/dom/size.cpp

examples/dom/spinner.cpp

examples/dom/style_blink.cpp

examples/dom/style_bold.cpp

examples/dom/style_color.cpp

examples/dom/style_dim.cpp

examples/dom/style_gallery.cpp

examples/dom/style_inverted.cpp

examples/dom/style_underlined.cpp

examples/dom/vbox_hbox.cpp

examples/html/test.html.disabled