Test cleanup.

Eliminate the explicit account module.

Angular is smart enough to not instantiate the application until all
pending scripts have been loaded. That means that we can load optional
components by simply appending the script tags. We already load the
account component after the app component. By having the account
component attach its controllers and configuration functions to the
existing 'h' module, rather than defining a new angular module, the
app can avoid having a dependency on 'h.account'. This removes the
requirement that integrators define this module. Instead, they can
just attach a configuration function to the main module if they need
to configure the identity provider.

I have a mild preference for this pattern, since strictly speaking no
account module needs to be present. With a little morke tweaking, the
interface could be made to not have a sign in link and operate in an
anonymous mode by default, assuming that the server requires no
authorization to annotate.

The assertion is not what we want, nor is the argument that is passed
to the `withToken` callback (which is the payload). We want the encoded
token string, which will be inside the Auth plugin.

Improve viewfilter

Remove focus state when clicking on toolbar buttons

Update Firefox extension

Remove unused h.notification.domain_mailer

Backend has changed to allow this a long time ago,
and as stream page performs frontend filtering too,
backend results weren't shown.

Fix hit area for dropdown menu items

Build production versions of the extensions on Travis

Now all items contain anchors which are set to display: block this
keeps all implementations consistent and improves accessibility.

Add MathJax config option allign left.

Previously, MathJax was rendering display style math allign: "center",
while KaTeX rendered allign: "left". This has been addressed.

When the showHighlights option is passed to the guest constructor as
we do with the extensions.

This prevents the focus style continuing to be applied after a toolbar
button has been clicked.

Fix tag search.

This escapes any special url characters in the term

ES stores the tag field as tags

Fix #1879

This contains some potentially confusing code and was clarified by
Randall here: http://git.io/HvLCLA

Set the standalone conversation as the viewer root

This special cases the threads that are styled as cards rather than
replies and allows them to be styled accordingly.

Now the thread is not using negative margins this isn't required.

Fix #1803

Replace documentHelpers with baseURI + URL API

Rather than have a service, ``documentHelpers``, that exposes a value,
``baseURI``, and a function, ``absoluteURI``, decorate ``$document``
so that it's guaranteed to have a ``baseURI`` property and use the
previously included ``URL`` constructor as a standard way to get parts
of a URL.