[giow] (3) Make <base> elements not be affected by changes by to the document's address
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=18459
Affected topics: HTML

git-svn-id: http://svn.whatwg.org/webapps@7962 340c8d12-0b0e-0410-8428-c7bf67bfef74

Author:    ianh <ianh@340c8d12-0b0e-0410-8428-c7bf67bfef74>