rm'd unkown attribute rule

more info: https://github.com/scrooloose/syntastic/commit/a956a814323225f9fce873a14a3d8edc027b7aa5#commitcomment-4537304
Added WAI-ARIA attributes

Added all WAI-ARIA aria-* and role attributes.

http://www.w3.org/TR/wai-aria/states_and_properties#state_prop_def

These are used to create accessible web applications.
Remove hgroup, it is non-conforming

http://www.w3.org/html/wg/drafts/html/master/obsolete.html#hgroup
Merge pull request #854 from kaleb/patch-3

Html/tidy: remove bogus "attribute \"[+" ignore rule.
Merge pull request #855 from kaleb/patch-4

html/tidy: Add WAI-ARIA attributes
Merge pull request #856 from kaleb/patch-5

html/tidy: Remove hgroup, it is non-conforming
Merge branch 'master' into registry_cleanup