chore(core): move compiler out of core

BREAKING CHANGE

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

modules/angular2/src/transform/template_compiler/change_detector_codegen.ts

@@ -4,7 +4,7 @@ import {
 
 // Note: This class is only here so that we can reference it from TypeScript code.
 // The actual implementation lives under modules_dart.
-// TODO(tbosch): Move the corresponding code into angular2/src/core/compiler once
+// TODO(tbosch): Move the corresponding code into angular2/src/compiler once
 // the new compiler is done.
 export class Codegen {
   constructor(moduleAlias: string) {}