Rename entry point for annotator CSS bundle

Restructure sidebar styles in source tree

Rename entry points for annotator and sidebar bundles to 'index.js'

Update the docs for config options available to third party publishers.

Rename the entry point for the annotator CSS bundle so that it matches
the name of the source directory from which the bundle is compiled and
also the name of the corresponding JS bundle once that is renamed by
hypothesis/client#633

- Move the sidebar-specific styles into `styles/sidebar` and the
  component-specific styles into `styles/sidebar/components`. This mirrors
  the structure of the JS code in `src/`.

- Rename the entry point for the sidebar's style bundle from "app.scss"
  to "sidebar.scss" to make it more obvious what is in the generated
  "sidebar.css" bundle.

This move highlights some inappropriate dependencies between style
modules and an unclearly structured assortment of "stuff" shared by both
annotator and sidebar bundles in shared files in `src/styles`. There is
probably a fair amount of unused code in there as well. Cleaning that
up will happen in separate commits.

Rename the entry points to the more conventional 'index.js' for the
benefit of new visitors to the codebase and also for consistency across
the different bundles that make up the client.

Remove create account banner

The template no longer uses this property.

The text is potentially inappropriate in the context of
publisher-managed accounts where the account might not be free and the
user might not be able to create one themselves.

In the first party account context we agreed that the banner is a bit
redundant anyway. See
https://hypothes-is.slack.com/archives/C07NXBDNW/p1510080494000386

Disable close btn when the classic theme is on. Also fix errors with …

Disable close btn when the classic theme is on. Also fix errors with the preferences object being obsent from session state initially.

Remove unnecessary config in test.

Bundle the clean theme related config options into the theme = 'clean…

Some of the config settings don't work well with the clean theme. Some others don't work
without the clean theme. It would be better to remove the following config options and
have each of these elements tied to the over all 'theme' of the sidebar for consistency:
disableToolbarCloseBtn
disableToolbarMinimizeBtn
disableToolbarHighlightsBtn
disableToolbarNewNoteBtn
disableBucketBar
enableSidebarDropShadow
enableCleanOnboardingTheme

See https://github.com/hypothesis/product-backlog/issues/380

Show the shorter version of the empty annotations/notes message when …

Don’t link tags to activity pages on eLife

The stream page was replaced by the search page. Update some old
references to the stream in the tests.

Tag search pages aren't supported for third-party annotations in h, so
don't link to them from the client.

Fixes https://github.com/hypothesis/client/issues/616

Fix out of date account-id fake

The fakeAccountID object in annotation-test.js was out of date: it
contained only a username() function that annotation.js doesn't call
anymore, and did not contain the isThirdPartyUser() function that
annotation.js _does_ call.

The tests were still passing because annotation.js's isThirdPartyUser()
method, which call's account-id's isThirdPartyUser(), wasn't tested. Add
an integration test for this method to catch this.

I've also moved fakeAccountID out into its own variable with a name,
instead of it just being an anonymous object literal. This makes it more
explicit. For example if account-id's API is changed, you can just grep
the code for fakeAccountID to find all the fakes that need to be
updated.

Move the annotationComponent() function into the describe() scope nearer
to where it's actually used. This puts the code nearer to where it's
used and is going to be useful in the next commit when it's going to be
changed to make use of one of the fake variables in that scope.

Don't show page share button on eLife pages

Remove traces of persona.js

persona.js was renamed to account-id.js.

persona.js was moved to account-id.js in
35f1a03d but this proxyquire call is
still patching persona.js not account-id.js.

Don't show the "Share this page" button in the top-right of the sidebar
on pages, such as eLife's, that have both an embedded Hypothesis client
and a services config including their own `authority` string.

The "Share this page" button is a Via link, and Via doesn't work with
pages using a third-party authority config.

Fixes https://github.com/hypothesis/client/issues/615

Show the shorter version of the empty annotations/notes message when the sidebar tutorial is displayed
and the new note button is enabled.

Fixes https://github.com/hypothesis/client/issues/610

Don't show share dialog if no incontext link

If the annotation received from the API contains no incontext link (as
is the case with third-party annotations, for example) then don't render
the annotation share dialog that contains the incontext link.

Dont hyperlink annotation timestamps when the annotation has no href