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.

For readability, especially in light of the injection annotations,
split the app configuration functions in ``app.coffee``.

Clean up unused and duplicate TextHighlight code.

Remove URL fragments

Starve the monkey

As suggested in:

    https://github.com/hypothesis/h/pull/1868/files#r23171034

Annotator#isAnnotator provides better answers as of
openannotation/annotator@368b5cf.

Remove past_data

The processed streamfilter does not send back anything,
more_hits message can give back annotations

This commit is intended as a pure refactoring. No behaviour should be
changed.

There is no need for a variable name if it is just returned immediately.

Allow simple usernames

Simplify the front-end code that transforms annotation permissions
objects into ACLs. Since the front-end does not have to be exposed
to the system principals and special "all" grant used by Pyramid it
only needs to have special handling of the "group:__world__"
principal; others are unused.

Allow the persona filter to pass invalid account URIs through unharmed.

Replace Annotator with dist build

Replaces the inlined CoffeeScript with a vanilla v1.2.x Annotator from
upstream!

Move on to vanilla annotator + a herd of monkeys.

1796 add any field handling for search api

Resolve user authorization before view render.

This commit moves most customisations of the upstream Annotator v1.2.x
into annotator_monkey.coffee, which monkeypatches the Annotator object.
Customisations required by the anchoring subsystem are moved into the
"enhanced anchoring" plugin.

With this change, we should be able to replace our inlined Annotator
source with the built JavaScript for upstream Annotator!

This file provides an abstract base class that's only used in one place,
so this commit just moves it into the one place where it's used.

Avoid having to watch the user in route controllers at all by resolving
it as a prerequisite of the routes, much like the store bootstrap. The
user may still be ``null`` but it will not be ``undefined``.

For clarity, the $routeChangeStart handler is changed back to a
function, ``cleanupAnnotations``, that is called explicitly from
the user watcher in the ``AppController`` right before the route
reloads.

Set the FF addon version at build time