Organize sky/framework a bit

- Removed out-of-date README.md
- Moved fling-curve into the animation directory because it's part of the
  animation behavior of the system.
- Moved view-configuration into the theme directory because it's a collection
  of constants similar in flavor to the colors and the shadows. Eventually
  we'll want to make the theme configurable and have these all together will
  hopefully make that easier.
- Moved dom-serializer into tests/resources because it is used only by tests.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/980423002

examples/fn/widgets/widgets.dart

 library widgets;
 
 import '../lib/fn.dart';
-import '../../../framework/fling-curve.dart';
 import '../../../framework/animation/curves.dart';
+import '../../../framework/animation/fling-curve.dart';
 import '../../../framework/theme/colors.dart';
 import '../../../framework/theme/shadows.dart';
 import 'dart:collection';

framework/README.md

-SkyElement
-===
-
-SkyElement is the framework for creating...yup...Sky Elements. It take heavy
-inspriation from [Polymer](www.polymer-project.org) and isn't very fully
-featured...yet
-
-Declaring an element
---------
-```HTML
-<import src="../path/to/sky-element.sky" as="SkyElement" />
-<template>
-  <my-other-element>Hello, {{ place }}</my-other-element>
-</template>
-<script>
-// SkyElement takes a single object as it's only parameter
-SkyElement({
-  name: 'my-element', // required. The element's tag-name
-  attached: function() {
-    this.place = 'World';
-  }, // optional
-  detached: function() {}, // optional
-  attributeChanged: function(attrName, newValue, oldValue) {} // optional
-});
-</script>
-```
-
-Note that an element's declared ShadowDOM is the previous `<template>`
-element to the `<script>` element which defines the element.
-
-Databinding
---------
-SkyElement's databinding support is derived from Polymer's. At the moment,
-there are some key differences:
-
-There is not yet support for
- * Declarative event handlers
- * Inline expressions
- * Self-observation (e.g. `fooChanged()` gets invoked when `this.foo` is changed)
- * Computed properties (e.g. the computed block)
- * Conditional attributes (e.g. `<my-foo checked?="{{ val }}"`)
-
- Also, because there are so few built-in elements in Sky, the default behavior
- of HTMLElement with bindings is to assign to the property. e.g.
-
- ```HTML
- <my-foo bar="{{ bas }}">
- ```
-
- Will not `setAttribute` on the `my-foo`, instead it will assign to the `bar`
- property of `my-foo`. There are two exceptions to this: `class` & `style` --
- those still`setAttribute`.

framework/sky-scrollable.sky

@@ -37,8 +37,8 @@
 <script>
 import "dart:math" as math;
 import "dart:sky";
-import "fling-curve.dart";
-import "view-configuration.dart" as config;
+import "animation/fling-curve.dart";
+import "theme/view-configuration.dart" as config;
 
 @Tagname('sky-scrollable')
 class SkyScrollable extends SkyElement {

tests/resources/dump-as-markup.sky

-<import src="/sky/framework/dom-serializer.sky" as="DomSerializer"/>
+<import src="dom-serializer.sky" as="DomSerializer"/>
 <script>
 import "dart:sky";
 import "dart:sky.internals" as internals;