Remove iframe size check

Since we now only enable annotation of iframes that are explicitly opted
in by the containing page, we can avoid checking the size of the iframe
as well. That check was originally added to filter out ads and hidden
iframes.

This resolves an issue with Epub.js where an iframe initially has zero
width. This is because book content is laid out into a variable number
of fixed-width columns and the iframe's width is set to the total width
of all columns. Until the content is loaded, the number of columns and
hence the width, is zero.

Stop exporting the main annotation layer object as `window.annotator`

The main application object in the code which runs in the host page was
made visible to other code on the page as `window.annotator`.

This export existed for legacy reasons (the client's Annotator.js
heritage), is not part of the public API of the client and we do not
make any effort to avoid breaking changes to it between releases.
Removing this export should prevent third parties writing code which
depends on its interface.

Adjust the preferred initial size of the OAuth popup window.

Fix timestamp tooltips in annotation cards

Rewrite viewFilter service and fix incorrect handling of any-field query terms in client-side search

Use profile display name in account menu

Add more vertical and horizontal space per the designs for what the
popup view should ideally look like [1], if the screen size is large
enough and the user agent permits it.

[1] https://github.com/hypothesis/product-backlog/issues/348

Timestamps on annotation cards are supposed to display the full date and
time in the tooltip. This didn't work because `ng-title` is not a thing.

Render display name in new annotations

Render the display name if set

Populate the `user_info` field for new annotations from the logged-in
user's profile. This enables new annotation cards to render the user's
display name instead of their username if they have set one.

This logic is currently in the annotation component init function for
consistency with how the `user` field is initialized. However, it really
ought to be in the code that handles the `addAnnotations` Redux action.

If the user has set a display name, render that in the account menu
instead of their username.

If the display name is provided by the server in the annotation's
`user_info` field, render it instead of the username in annotation card
headers.

Fix OAuth popup being blocked by pop-up blocker in Firefox and IE

Use vendor-prefixed `msCrypto` property for IE 11

Remove unused refresh timer variable in OAuth service

Together with [1] this fixes the OAuth popup failing to appear when
clicking "Log in" in IE 11.

[1] https://github.com/hypothesis/client/pull/537

Make annotation of iframes opt-in

When the user clicked the "Log in" link, the URL of the
"oauth.authorize" endpoint was fetched via an async Promise-returning
method before the `window.open` call was made. This meant that the
`window.open` call did not happen in the turn of the event loop that was
triggered by the user action and so Firefox & IE's popup blockers deemed
the call to have happened outside the context of a user gesture and
prevented the window being opened.

Chrome, Safari & Edge have different heuristics and did not block the
popup before.

Fix the issue by opening the window directly when the user clicks on the
"Log in" button, at a dummy URL ("about:blank"), and then changing the
window's location once the authorization endpoint URL has been fetched.

Fixes #534

This was missed during 28bdb52f

The client's iframe support is not yet robust enough (see
https://github.com/hypothesis/client/issues/530) to enable it
automatically for all iframes on arbitrary web pages.

To support the needs of EPUB viewers and others in the meantime while
preventing problems on eg. pages with larger numbers of iframed ads,
require the publisher to opt iframes into annotation by adding the
"enable-annotation" attribute to them.

Run `prettier` on `frame-util.js` to fix up some minor formatting
inconsistencies.