[giow] (2) Revamp 'input' and 'change' event logic for <input> elements. The primary goal here is to make 'input' events fire on type=checkbox, type=radio, and type=file, but this also improves the way other things here are phrased.
Fixing https://www.w3.org/Bugs/Public/show_bug.cgi?id=23449
Affected topics: HTML

git-svn-id: http://svn.whatwg.org/webapps@8367 340c8d12-0b0e-0410-8428-c7bf67bfef74