Fix issue with document.body.innerHTML

It used to end up calling `document.body.removeChild(realNode)` which does not
work because we have hijacked document.body.removeChild to only work with
wrappers.

Fixes #97
Merge branch 'remove-child-needs-to-use-original' of git://github.com/arv/ShadowDOM into arv-remove-child-needs-to-use-original

Conflicts:
	test/HTMLBodyElement.js