[giow] (3) Fix <area> to match <a> in terms of security checking. Also, some editorial fixes.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=21654
Affected topics: DOM APIs, HTML, Video Text Tracks, Workers

git-svn-id: http://svn.whatwg.org/webapps@7836 340c8d12-0b0e-0410-8428-c7bf67bfef74