feat(animate): adds basic support for CSS animations on enter and leave

Closes #3876

tools/broccoli/trees/browser_tree.ts

@@ -40,6 +40,7 @@ const kServedPaths = [
   'benchmarks_external/src/static_tree',
 
   // Relative (to /modules) paths to example directories
+  'examples/src/animate',
   'examples/src/benchpress',
   'examples/src/model_driven_forms',
   'examples/src/template_driven_forms',

tools/broccoli/trees/node_tree.ts

@@ -20,6 +20,7 @@ module.exports = function makeNodeTree(destinationPath) {
     include: ['angular2/**', 'benchpress/**', '**/e2e_test/**'],
     exclude: [
       // the following code and tests are not compatible with CJS/node environment
+      'angular2/test/animate/**',
       'angular2/test/core/zone/**',
       'angular2/test/test_lib/fake_async_spec.ts',
       'angular2/test/core/render/xhr_impl_spec.ts',