refactor(xhr): move render's xhr implementation to render/

The existence of this module in the services/ folder led some to believe xhr
is meant to be a general-purpose http library.

Fixes #2305

modules/angular2/src/render/dom/compiler/template_loader.ts

@@ -4,7 +4,7 @@ import {Map, MapWrapper, StringMapWrapper, StringMap} from 'angular2/src/facade/
 import {PromiseWrapper, Promise} from 'angular2/src/facade/async';
 import {DOM} from 'angular2/src/dom/dom_adapter';
 
-import {XHR} from 'angular2/src/services/xhr';
+import {XHR} from 'angular2/src/render/xhr';
 
 import {ViewDefinition} from '../../api';
 import {UrlResolver} from 'angular2/src/services/url_resolver';

modules/angular2/src/render/dom/shadow_dom/style_inliner.ts

@@ -1,5 +1,5 @@
 import {Injectable} from 'angular2/di';
-import {XHR} from 'angular2/src/services/xhr';
+import {XHR} from 'angular2/src/render/xhr';
 import {ListWrapper} from 'angular2/src/facade/collection';
 
 import {UrlResolver} from 'angular2/src/services/url_resolver';