feat(views): adds (de)hydration of views and template vars.

Dehydrated views are views that are structurally fixed, but their
directive instances and viewports are purged.

Support for local bindings is added to the view.

modules/change_detection/test/parser/context_with_variable_bindings_spec.js

@@ -0,0 +1,42 @@
+import {ddescribe, describe, it, xit, iit, expect, beforeEach} from 'test_lib/test_lib';
+import {BaseException, isBlank, isPresent} from 'facade/lang';
+import {MapWrapper, ListWrapper} from 'facade/collection';
+import {ContextWithVariableBindings} from 'change_detection/parser/context_with_variable_bindings';
+
+export function main() {
+  describe('ContextWithVariableBindings', () => {
+    var locals;
+    beforeEach(() => {
+      locals = new ContextWithVariableBindings(null,
+          MapWrapper.createFromPairs([['key', 'value'], ['nullKey', null]]));
+    });
+
+    it('should support getting values', () => {
+      expect(locals.get('key')).toBe('value');
+
+      var notPresentValue = locals.get('notPresent');
+      expect(isPresent(notPresentValue)).toBe(false);
+    });
+
+    it('should support checking if key is persent', () => {
+      expect(locals.hasBinding('key')).toBe(true);
+      expect(locals.hasBinding('nullKey')).toBe(true);
+      expect(locals.hasBinding('notPresent')).toBe(false);
+    });
+
+    it('should support setting persent keys', () => {
+      locals.set('key', 'bar');
+      expect(locals.get('key')).toBe('bar');
+    });
+
+    it('should not support setting keys that are not present already', () => {
+      expect(() => locals.set('notPresent', 'bar')).toThrowError();
+    });
+
+    it('should clearValues', () => {
+      locals.clearValues();
+      expect(locals.get('key')).toBe(null);
+    });
+  })
+}
+