Stop Travis from uploading docs

Clean-up around progress indicators.

We now upload these from Chromium infra.

Assert that custom painters balance save/restores.

Ignore generated/ instead of ios/

Move StepTween to tween.dart.

Move _buildIndicator() methods to be next to the build() methods they're
used from, so that reading the code is easier.

Fix typos, add some comments, style nits.

ImageCache should be a public type

Fix style nits in progress_indicator.dart

toString for Tween and ThemeData

We expose `imageCache`, which is an ImageCache, but previously the class
was private which means there was no documentation for the methods on
that object.

Fixes #1750

This patch tightens up the imports in this file and hides some more of
the implementation details by making RepeatingCurveTween and StepTween
private.

Also, removed a CurvedAnimation with a linear curve.  That's not needed
because the animation controller itself is an Animation<double>.

This animation expands/collapses an arc that's 3/4ths of a circle.
The next iteration begins where the previous appeared to finish.
This happens while the whole thing rotates, such that the starting point of each
expansion moves in a star-wise pattern around the circle.

See:
https://www.google.com/design/spec/components/progress-activity.html
(note: the video here demonstrating this animation is actually slightly incorrect...
we'll hopefully update it soon)

Allow users to upgrade their iOS engines without removing their edits to the Xcode project

Add versionCode and versionName to default Android manifest

These are required to upload to the store.

Fixes #1006

rename the apk/ directory to android/

Ticker typedef had no defined return type

Refactor MultiDragPointerState to support delays

...even after winning the arena.

Write a REVISION file in the ios directory to aid in version checks

Added a Card demo

Explicitly specify the sdk and arch when building for an iOS device

Change the text/selection value API of the input field

Provide a Draggable that starts on drag