Show spinner in search bar during requests

This is unnecessary and less obvious than the toggle button, which
means it's not worth the egregious fail of preventing interaction
with scrollbars, etc.

This has been deemed too clever.

Mobile support

Android and iOS devices can now create annotations. Obsolete
flags on the annotator object are removed.

This places the up/down navigational buckets on a z-plane with the
toolbar buttons and ensures that the other buckets pass under them
while moving on and off screen.

It is potentially confusing if, upon reaching the start or end of
highlights, the navigational buckets don't seem to do anything. At this
point, the first or last highlights are visible but the buckets seem to
indicate that the highlights are still off screen.

Change the buckets to mantain a count of the annotations that are
strictly off screen.

Since the toolbar is no longer dynamically shown the position of
the "up" bucket should statically be set to a higher offset top.

By having the up/down navigational buckets scroll highlights
into view they only come to the inside edge of the viewport. This
is not sufficient to get them far enough into view that they leave
the navigational buckets. Therefore, it's not sufficient to take
the next closest of the highlights in said buckets when attempting
to scroll further, since it may already be on screen.

Implement `getBoundingClientRect` for `TextHighlight` and use that
to check whether a highlight is off screen before deciding to
scroll to it.

Address usability issues

Analytics

A `$rootScope.$apply` is removed from the `on` method of the iframe-
side cross-frame code. This code was incorrect because the registration
of a handler does not require a digest cycle. This was seemingly
innocuous before, but adding the analytics module changed the order
of injection resolution such that it caused a problem wherein a digest
cycle happens before angular has even finished compiling the DOM and
processing ng-template scripts. The result was that route templates
were not being read from the template cache and 404s resulted on
stream navigation and auth pages.

- Toolbar always open
- Show anotations changes icon and tooltip when toggled.
- .annotator-h1-focused color darkened

SetTool was a holdover from highlight mode days and doesn't do anything.

Introduce _splitTerm() for searchFilter service

Moved out from _tokenize() as a separate function to split
a search term properly into filter, term because toObject()
must call this too.

Fix #2142

Revert "Merge pull request #2086 from hypothesis/2052-scroll-to-sign-in-form-on-clicking-sign-in-link"

This reverts commit ca535b6d8a81af343489120e02326c34f71a3d46, reversing
changes made to 0988bffc2d8c968ff35bea177ac65868796b8563.

CLI utility to send invitations

Test form-input interaction with form-validate

Fix #930

Since changing the size of button icons in de75319 we can now style
these actions with button markup and the btn-clean class. The last
remnants of .magicontrol go away.

This reverts commit 08d991f066e48c0388ff76ce24a611c1f553a096, reversing
changes made to d488f9c491c0334ee4f46210ba17127df169a9e6.

Mock and test that half of the interaction, and in doing so show that
it's also optional to use the validator with the input.

Scroll to new annotations on creation

Use domain as citation title if no document

Partly a reaction to fce1f2c, which made icons overall smaller.