LayoutBlock::inline_wrapper() is supposed to return an inline wrapper,
a special anonymous block element intended to wrap inline children of
a block element that also has block children. Add a check for whether
the existing block child element is anonymous (refers to a DOM node),
and if it's not create a new anonymous wrapper.
Instead of LibGUI and WindowServer building their own copies of the drawing
and graphics code, let's it in a separate LibDraw library.
This avoids building the code twice, and will encourage better separation
of concerns. :^)
