Since the `<thread-list>` is now contained within a scrollable element
which is not `document.body`, it needs to scroll that element rather
than the window in order to scroll the element into view.

 * Remove the hard-coded selector used to find the scroll root and
   instead search for the closest ancestor element to the
   `<thread-list>` whose computed style has `overflowY` set to `scroll`.
 * Set the scroll root Element's `scrollTop` to scroll the thread list
   instead of calling `window.scroll`
 * Compute the maximum scroll offset based on the `scrollTop` and
   `scrollHeight` properties of the scroll root element instead of
   using `document.body.scrollHeight`.
 * Update tests for `<thread-list>` to check for the scrollable
   ancestor being scrolled instead of the window.

Convert `<top-bar>` to a component

Add tests that callbacks and properties are passed down correctly to
child components.

`frame` is never assigned anywhere and `ng-cloak` is unnecessary since
the HTML for the `<top-bar>` component is not present in the page when
it loads but is added by Angular after the app has booted.

Fix incorrect additions of 'vm.' prefix that were added when converting
`<top-bar>` to a component and a missing 'vm.' prefix in the call to log
out.

Convert `<hypothesis-app>` to a component

Rename the modules and templates for the `<hypothesis-app>` component to
match the component name, following our conventions.

Fix scrolling to new annotations

Convert AnnotationViewerController to a component

Output logs from s3-npm-publish Docker container

Since #306 which set the height of the `<hypothesis-app>` container
element to 100%, the height of `document.body` is now equal to the
window's `innerHeight`. As a result, `document.body.clientHeight` now
returns the same value as `window.innerHeight` and `scrollOffset()`
returns 0.

Fix this by using `scrollHeight` instead of `clientHeight`, which takes
into account the height of all of the body's descendant elements,
including the `<thread-list>`.

This calculation would still return the wrong result if the
`<thread-list>` were ever placed in a separate scrolling container
within the sidebar app window, but that is an acceptible limitation for
now.

When this test was converted from CoffeeScript to JS, the implicit
return of the Promise was not converted to an explicit return. Hence the
test would sporadically fail depending on when the Promise callback got
executed.

To help debug publishing failures, output logs from the container.  See
https://hypothes-is.slack.com/archives/C076LQFA4/p1490705667081734

Convert `<markdown>` to a component

Convert AnnotationViewerController to an `<annotation-viewer-content>`
component following the same refactoring that was applied to the sidebar
and stream.

Convert StreamController to a component

Strikethrough & apply greyscale/contrast effects to hidden annotations

Convert the `StreamController` controller which provides the logic for
the content area of the stream into a `<stream-content>` component.

Convert `WidgetController` into a `<sidebar-content>` component

Rename `textClass` input to `customTextClass` as per CR feedback.

Adding auth metrics for login, logout, and signup requested

Adding analytics to share functions

This function is no longer inherited from the parent scope since
`<sidebar-content>` is now a component.

Since this helper function is only used by the sidebar, move it
to the SidebarContentController controller.

Convert 'WidgetController' into a `<sidebar-content>` component which
uses `sidebar_content.html` as a template and convert the route for the
sidebar into a trivial template which just renders this component.

 * Move `widget-controller` to src/sidebar/components/sidebar-content.js

 * Move various helpers for the sidebar content template from the scope
   to the controller, in line with other components.

 * Pass the "auth" and "search" scope properties from the AppController
   instance explicitly to `<sidebar-content>`, since components do not
   inherit scope properties automatically.

Split viewer.html template into one template per app type