Fix broken promises in IE

Fixes #2953.

We support IE10/11, neither of which define Promise globals, so make
jshint warn if we use Promise without explicitly defining it (by
importing a polyfill).

Fix #2810: no error on sign in to unactivated account

Finish indirection through storage

Simpler version management

Mark deployed features as pending for removal

I broke this in f7b519d, it seems.

Fix RavenJS initialization in app and stream

Improve Chrome sidebar injection error detection and handling

Improve capture of sidebar injection errors

Put the Error first as the most important argument, followed
by a string describing when the error happened, followed by optional
context information.

This also reduces unnecessary nesting in the 'extra' field
of the captured exception that is sent to Sentry.

app.coffee failed to initialize Raven because it looked for
config info in window.RAVEN_CONFIG instead of the #hypothesis-settings
<script> tag.

This commit makes the web service expose the Raven config info
to the site and the application in the same way, using JSON <script>
tags which are compatible with the strict CSP policy used by
the Chrome extension.

 * Expose and consume config info in the same way on
   the site and in the app.

 * Refactor settings.js to make it independent of Angular, for
   use on the site.

Fixes #2938

 * Capture the tab URL as context when injecting the sidebar
   fails, for use in debugging.

 * Switch tests to use the toResult() helper instead of
   Promise.catch() to handle assert errors inside
   catch blocks properly.

 * Handle the Error-like objects used by chrome.extension.lastError
   better.

   When a Chrome async API fails, it sets chrome.extension.lastError
   to an Error-like object with a 'message' property. Since this
   object is not an instance of Error, RavenJS stringified it
   with .toString(), resulting in an unhelpful '[object Object]'
   message in Sentry.

   This commit adds logic to extract out the message property
   of such objects when capturing exceptions.

Merge pull request #2929 from hypothesis/2928-restore-counting-of-private-and-group-annotations-in-badge

Restore counting of private and group annotations in badge

Specify the minimum Chrome version in the manifest

Fix base URL not being specified for /app/dismiss_sidebar_tutorial route

Simplify server side auth code

Add a PENDING_REMOVAL bucket for features on their way out

The dismiss_sidebar_tutorial session action overrode the whole
URL, including replacing the base URL with just '/app'. Therefore
it would have failed when app.html's origin did not match the service
URL - as in the Chrome extension.

 * Pass the complete URL for the dismiss_sidebar_tutorial action

 * Remove several unused actions from session.js that have been
   replaced by server-rendered forms

 * Add test for dimiss_sidebar_tutorial action

Add automated retry with backoff for session loads

Always count annotations with the correct userid

Don't autofocus the group share link

Unfortunately, on group pages for groups who have annotated lots of
documents, this results in a rather confusing jump to the bottom of the
page.

Fixes #2917.

If a session load fails, subsequent calls to
session.load() would trigger another request immediately.
Together with feature flag checks triggering session.load(),
this could result in a cycle if no network connection was present:

 1. App loads during initial digest cycle, 'flag.featureEnabled()'
    is called to test whether to show certain UI elements
 2. session.load() is triggered
 3. session.load() fails and the HTTP response error triggers
    a digest cycle
 4. GOTO 1

This commit resolves the problem by automatically retrying
session.load() calls with an exponential backoff.

Standalone websocket server

Group page update

Add help text to nipsa form

Fix client-side router on site

Don't 404 if a user visits an activation link twice

Do not update the group for existing annotations on edit

Fix flash of 'Create Account' banner in stream

Admin account deletion

Remove the need to specify the Chrome extension ID when building with bundled assets

Whenever an annotation was edited, its current group
was set to whichever group was focused in the UI.

Our current model does not allow for moving annotations
between groups however. The only time when annotations
should have their groups set is when the annotation
is newly created and when switching groups before saving
the annotation. We already have separate logic to deal
with both of these cases.

Fixes #2902

Fix user annotation query in admin panel

The JS for the group share page failed to load
because of an incorrect comparison of the result
of String.match() against a number and also
because of an attempt to load Bootstrap
unnecessarily on this pages.

This commit fixes the issue and prepares us for
adding new pages in future by:

 * Adding a client-side micro-router to simplify running
   page-specific JS

 * Only loading the Bootstrap components on pages that
   actually need it.

Fixes #2867