chore(core): move compiler out of core

BREAKING CHANGE

All imports from 'angular2/core/compiler' should be changed to 'angular2/compiler'.

modules/angular2/test/compiler/spies.ts

@@ -0,0 +1,7 @@
+import {XHR} from 'angular2/src/compiler/xhr';
+
+import {SpyObject, proxy} from 'angular2/testing_internal';
+
+export class SpyXHR extends SpyObject {
+  constructor() { super(XHR); }
+}