Fixes #4935.

Issue #4922

* Pass in and use the htmlhint module required.
* Check for verify() and try HTMLHint.HTMLHint if missing because of
  module nesting. it's require('htmlhint').HTMLHint in node.

Issue codemirror/google-modes#8

This is opt-in, the plugin needs to produce message_html instead of
message to be rendered as HTML.

This should help developers building this functionality out that may not
realize they need to source the linting library seperately.

Issue #3059

So that the addon doesn't try to put a single DOM node in two places

Closes #4848

Issue #4839

Closes #4839

Issue #4824

This prevents the test case search_expandingCaseFold from hanging in
Firefox 54 on Linux.

Issue #4819

Issue #4784

Issue #4787

Default this to true when the fat-cursor style is active.

Issue #4803

Since the vim bindins are depending on that

Issue #4712

Closes #4683

Add tag parameter to xml-fold findEnclosingTag to find enclosing tag of particular type.

Closes #4641

Issue #4627

Identifiers that contain the identifierQuote like a table named
my"table are now doublicated correctly (e.g. quoting produces:
"my""table"). This fixes 2 failing tests, but 2 others still fail.

Closes #4621