[giow] (3) require that document.images and friends always return the same object. This'll be great until either we find that browsers don't always return the same object or until someone notices that this implies that two different Documents will return the same object.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=26566
Affected topics: DOM APIs

git-svn-id: http://svn.whatwg.org/webapps@8765 340c8d12-0b0e-0410-8428-c7bf67bfef74