Remove unneeded favicon HTML

`/favicon.ico` is the implied favicon location, so no HTML is needed in this case. See http://mathiasbynens.be/notes/rel-shortcut-icon for more info.
Added `lang` attribute to `html` element.
'xhtml' > 'html'

At some point, we all need to let our exes go.
Merge pull request #9 from potch/patch-2

'xhtml' > 'html'
Merge pull request #6 from grantpalin/master

Page language attribute
Merge pull request #4 from mathiasbynens/patch-1

Remove unneeded favicon HTML
Remove optional trailing slashes