Upload the client to the S3 bucket behind cdn.hypothes.is after
publishing to npm. The service will then redirect requests for /embed.js
to cdn.hypothes.is/hypothesis

We decided to publish the client's assets to a Hypothesis-specific
domain because publishers (eg. https://internethealthreport.org) may
want to use CSP to restrict where assets are loaded from and they won't
want to whitelist the whole of npm.

This also gives us better control over caching headers used on assets.

Improves performance and includes a number of bug fixes. See
https://github.com/showdownjs/showdown/blob/master/CHANGELOG.md for
changes.

Several tests required small changes because the rendering of
`para1\n\npara2` changed from:

  `<p>para1</p>\n\n<p>para2</p>`

To the visually equivalent:

  `<p>para1</p>\n<p>para2</p>`

The release notes were missing on the GitHub Releases page for the
client for several recent releases. This happened because of incorrect
heading levels used for subsections within a release in the CHANGELOG
file.

Don't treat annotation quotes (TextQuoteSelector.exact) as HTML

The annotation quote, as plucked from the TextQuoteSelector, is not
HTML, and so shouldn't be rendered as such.

Fixes hypothesis/h#2896.

Add invisible threads list to allow render time saving for out of vie…

Add a new entry point script for the client application

Remove account settings and logout link from login control for 3rd pa…

For 3rd party users:
Remove the 'Account settings' link from the account menu
Remove the logout link from the account menu

Related PR:
https://github.com/hypothesis/client/pull/228

Fixes:
hypothesis/product-backlog#141

Disable the link to activity pages from user profile, if the user is …

correcting CC0 terminology

When serving the package's contents via an npm CDN such as unpkg.com, it
will be more convenient if the asset root URL provided by the service
refers to the root of the package rather than the root of the `build/`
dir.

Add additional preversion checks

Before bumping the package version and creating the tag, verify that:

 - Git is set up to create signed tags

 - GITHUB_TOKEN is set to an access token with permissions to push to
   the hypothesis/client repository

Fix quote anchoring in pages which add enumerable properties on Array.prototype

Update KaTeX to current version

The current 'katex' npm package now contains the fonts, so we can use
those instead of vendoring them into 'src/styles/vendor/fonts'.

Copy the WOFF 2.0-format fonts in addition to WOFF 1.0 format fonts
since modern browsers will prefer and try to fetch them first.

The current version of the 'katex' package now contains the CSS, so we
can consume it from the package instead of vendoring it into
'src/styles/vendor'.

Update KaTeX from v0.1.1 to v0.7.1.

This adds a long list of new features and fixes. See
https://github.com/Khan/KaTeX/releases for details.

It also enables us to remove the '\displayStyle' hack and use the
documented 'displayMode' option.

Fixes #165

Replace vendored KaTeX with package from npm

Wait for annotations to be fetched before displaying annotation counts in the frame.