Update to a new engine release

Teach the TimerPicker how to pick a time

The TimePicker can now actually pick a time. However, it doesn't understand AM
or PM and there's lots of visual polish missing.

Remove StateRoutes

Hide pub get output when updating flutter tool

Pin `package:test` to an exact revision

We use a number of non-public APIs in the test package, which makes our
dependency quite fragile. This patch pins a specific, known-good version. We
should update to the lastest version in a follow-up patch.

ignore .atom directories

Start working on a TimePicker

Improve unauthorized regexp

Fixes https://github.com/flutter/flutter.github.io/issues/101

Fixes https://github.com/flutter/flutter.github.io/issues/100

Expose the navigator in routes.

You can't actually pick a time with the time picker yet, but this patch adds
most of the plumbing.

Add drop down buttons to Material Gallery

Integrate Date Picker into material_gallery

Fix upload of composited scene with non-zero offsets

We weren't correctly offsetting the clips when uploading composited scenes. Now
we apply the proper offsets.

Allow run_mojo --android to specify location of flutter engine

Add package:flutter_test

This package contains WidgetTester, which is very useful when writing tests for
widgets.

Make it possible to run tests outside the Flutter repo

Add avatars to material chips

Fixes #464

This patch still requires a locally built engine. I'll remove the need for a
locally built engine in a future patch.

Fixes #278

Add basic support for material chips

http://www.google.com/design/spec/components/chips.html#chips-behavior

This patch adds support for deletable and non-deleteable chips, but doesn't yet
add support for contact chips. Also, demo the chips in a new Material Gallery
app that will let us demo our gallery of widgets in a single app.

more verbose error message

Avoid using transforms when simple offsets will do.

Rev engine, services, and sdk.