Additions to HTML standard

* More general rules
* Dropped "support" for <IE7
* Added lang tag to prevent having to add it for html5 validity
* Added utf-8 rule
* Added some information about semantics
I don't know why you want/need to specify an encoding. You need to know it before you start parsing a document, so if you include it inside content in the document, it's meaningless. Hence me thinking it was debunked years ago.