Add POST support to XHR as well as .status and statusText support

sky/tests/framework/xmlhttprequest/xhr.sky

Index: sky/tests/framework/xmlhttprequest/xhr.sky
diff --git a/sky/tests/framework/xmlhttprequest/xhr.sky b/sky/tests/framework/xmlhttprequest/xhr.sky
index c19f36d7dda0df945643d792eb78915a3f49c3c2..d7309637763be07f7c946bf9f21f7aaacfc72152 100644
--- a/sky/tests/framework/xmlhttprequest/xhr.sky
+++ b/sky/tests/framework/xmlhttprequest/xhr.sky
@@ -4,8 +4,6 @@
 <import src="/sky/framework/xmlhttprequest.sky" as="XMLHttpRequest" />
 <script>
 describe('XMLHttpRequest', function() {
-  this.enableTimeouts(false);
-
   it('should be able to fetch text files', function(done) {
 
     var xhr = new XMLHttpRequest();