Minor copy and style tweaks to the logged-out message

- We prefer "Hypothesis" in prose text to "Hypothes.is"
- Remove unwanted padding at the end of anchors.
- Say "sign in" rather than "log in," as we do everywhere else in the
  sidebar.
- Slight improvement to readability of call-to-action sentence by
  separating the "X or Y" clauses.
- Add a small gap between the two paragraphs.

Reintegrate annotation/document migration

Preserve selection when switching accounts

When visiting a direct-linked annotation (ie. #annotations:<id> is
present in the URL) we want to preserve the selection when the user
signs in, whether the annotation was private or in a group, in which
case they will need to sign in to see it, or public, in which case they
might need to sign in to reply.

Previously public direct-linked annotations became deselected when
signing in because they were unloaded when switching accounts, and this
fired the same ANNOTATION_DELETED event as when an annotation is
removed, which results in the annotation being removed from the
selection.

This commit enables the selection to be preserved by introducing a
different event within the app when annotations are unloaded vs.
deleted. When an annotation is unloaded, it is not removed from the
selection.

Fix a unicode warning

CSP Violation: form input onfocus

Merge pull request #3124 from hypothesis/sheetaluk/257-add-explanatory-text-below-public-focused-annotation-when-logged-out

Add message when user logged out and directed to an annotation.

When non-hypothesis users(or logged out users) are viewing a direct linked
annotation, we want to help them understand what they are looking at and
encourage them to sign up(or sign in).

Display a CTA message when:
* user is logged out
* user has landed on a DL
* there is a selection
* user has permissions to view the selection

Also,
* Add logo svg
* Update icomoon css
* Pull variables\.scss from 03cbef2

Fix the signature of NSQ error/exception handlers

Which fixes a CSP violation with having inline JavaScript.

Merge pull request #3146 from hypothesis/sheetaluk/294-as-a-user-i-want-to-be-able-to-find-out-who-is-a-member-of-a-group-i-m-in

Show list of group members in the group page.

Users want to see other users in the groups they belong to
and annotations each of these users have made and shared with a
group. This will help them decide how to share annotations with
their groups.

https://trello.com/c/rSUQLuos/294-as-a-user-i-want-to-be-able-to-find-out-who-is-a-member-of-a-group-i-m-in

List group memberships of user in admin interface

Use event constants consistently for events that are emitted
via $rootScope.

Convert AnnotationUI, AnnotationUISync from CoffeeScript to JS

Add Visual Studio Code project config file for JS

Merge pull request #3130 from hypothesis/sheetaluk/303-add-explanation-text-to-the-sharer-on-only-me-and-group-annotations

Add message to private and group annotations sharer.

Use specific Sentry DSN for the client part of H

Fix CSP violation on new homepage

Since we are not allowing inline styles with our CSP policy.

rearranging annotation icons

* Rearrange the annotation action icon positions.
* Add new colours for annotation action button labels.
* Replace icons for reply, edit, delete and share.
* Update style for loggedout users too.
* Update share icon in top-bar.

In combination with JSDoc annotations, this enables IntelliSense,
project navigation, inline documentation, refactoring and other goodies
using Visual Studio Code and other IDEs that integrate with TypeScript's
Language Service for JavaScript (aka.  'Salsa').

See https://code.visualstudio.com/docs/languages/javascript

The project file can be named either `jsconfig.json` without 'allowJs'
or `tsconfig.json` with the 'allowJs' config option enabled. I've opted
for `tsconfig.json` because that turns up better documentation on the
web and is recognized by more tools.

The project config file lives in h/static/scripts so that Visual Studio
only tries to parse and process .js files under that directory.  The
config file does support specifying the set of files to include, but
each file currently has to be listed individually. Glob support is
planned for the future. See
https://github.com/Microsoft/TypeScript/issues/1927

Support filtering test suites to run using '--grep' argument to gulp

Remove user status bitfield

Display message if a direct-linked annotation is not available

The image is specified using the `background-image` property since that
makes it easy to use the same relative URL when the app is served from
the extension and when it is served from the site.

If an annotation is selected but was not successfully loaded,
display a message in the sidebar indicating that the user does
not have permission to see that annotation.

Add support for filtering the tests that are run by Gulp test tasks
using '--grep <pattern>'.

This avoids the need to use the `(describe|it).only` test modifiers to
filter the tests that are run.

The pattern argument is a JS regex expression which is passed directly
to mocha as the 'grep' option.

eg. To start the app test suite in auto-restart mode, but only run tests
for the markdown editor, run:

  gulp test-watch-app --grep markdown

Replace '@p <ident>' with `ident` in JSDoc comments

Using '@p <ident>' to refer to parameters in JSDoc comments is not legal
syntax. Use Markdown backticks instead, ala. Angular's docs.

Switch to appropriate group and scroll to direct linked annotation when sidebar loads

Use more Pythonic way for the argument default value

Refactor feature caching

Change icon size in the bucket bar