This property previously had a "$$" prefix instead of the conventional
single "$" prefix for local-only properties of annotations for
historical reasons.

This is a followup PR to:
https://github.com/hypothesis/client/pull/126

* Rename the annotation property storing the local tag to `$tag`

This property previously had a "$$" prefix instead of the conventional
single "$" prefix for local-only properties of annotations for
historical reasons.

* Remove explicit copying of the `$tag` property in Object.assign() calls

The `$tag` property is now enumerable.

Update proxyquire

Fallback to last text node when we will fall into a null sibling node situation

Add PDF anchoring unit tests

Add a set of tests using a fake implementation of PDF.js'
PDFViewerApplication interface.

The initial set of tests simulate a nice born-digital PDF in which the
text layer of the PDF contains one <div> per line. In future we can
easily extend this to emulate the kind of structure that would be seen
when working with eg. an OCR-ed PDF

Update this dependency in preparation for updating the
dom-anchor-text-{quote, position} libraries.

The previous version indirectly used an old version of
combine-source-map that is not compatible with the inline source maps in
the newest versions of the dom-anchor-* libraries.

Remove the "-app" suffix from Gulp tasks

Remove AnnotationUIController

This is a holdover from when the Hypothesis service front-end and client
application lived in the same repository and the "-app" suffix was used
to indicate client-specific tasks. Removing this gives the tasks more
obvious names - "build", "build-js", "test" etc.

All of the functionality in this module is either unused or duplicated
elsewhere:

 * The $scope.{selectedAnnotations, focusedAnnotations,
   selectedAnnotationsCount} properties were unused.

   Note that there is a very similarly named `selectedAnnotationCount`
   scope property defined in `WidgetController` which _is_ used

 * The ANNOTATION_DELETED event handler duplicated another one in
   root-thread.js

This function expects an ID, not an Annotation

Add a set of HTML anchoring tests with expected failures

Fix formatting changes made via toolbar buttons not persisting

Add application state debugging utility

Add a set of tests which check that Ranges within a DOM tree are
correctly 'described' as selectors and then successfully converted back to
Range objects by anchoring.

The tests are derived from the suite of test cases collected for the
Annotator project at
https://github.com/openannotation/annotator/blob/v1.2.x/test/spec/range_spec.coffee

These tests found failures in describing ranges with position and quote
selectors in many cases and with a range selector in one case. The test
lists and checks these expected failures.

When making formatting changes to the text of an annotation with the
toolbar button without subsequently making a manual edit before clicking
Preview or Save, the onEditText() callback was never triggered and so
the unsaved changes were reverted when exiting edit mode.

This happened because onEditText() was only fired in response to the
'input' event which only occurs in response to programmatic, not manual
changes to the input's value.

Fixes #147

This adds a debug utility which prints the application state before and
after each action to the console when `window.debug` is set to a truthy
value.

Move session state to the Redux store

Fix prevent default override

In current versions of PDF.js, the `RenderingStates` enum is no longer
exported as a global, and the export method appears to be dependent on
the build configuration.

Since `RenderingStates` is a trivial enum, this commit fixes the problem
by just reproducing it in `pdfjs-rendering-states.js`.

Use Node v6.2 on Travis

This keeps things consistent with the version of Node used by h:

    https://github.com/hypothesis/h/commit/cc71f6c571829344e1f50a05b33504a2d42725d4

This fixes an error when trying to load the Hypothesis client on the
stream or standalone annotation pages, caused by both the stream app and
the sidebar app trying to set up a 'Discovery' server for annotation
'guests' to connect to.

With this change, only the sidebar app will set up a Discovery server
and hence it is now possible to annotate the stream and standalone
annotation pages.

Upgrade raven node package

Fix scrolling to direct-linked annotations

Fix adder from affecting website's height on load

The FrameSync service introduced in 55093ebb emitted an
ANNOTATIONS_SYNCED event which unintentionally had a different type for
the `tags` argument than the previous code (`string[]`, instead of
`Array<{tag:string}>`)

This commit updates the code in WidgetController to expect `tags`
to be of type `string[]`.

Fixes #129