fix(jqLite): support append on document fragment

previously jquery didn't support append on this node type, now it does
(since 1.8.x) so I'm adding this to jqlite as well.

src/jqLite.js

@@ -659,8 +659,9 @@ forEach({
 
   append: function(element, node) {
     forEach(new JQLite(node), function(child){
-      if (element.nodeType === 1)
+      if (element.nodeType === 1 || element.nodeType === 11) {
         element.appendChild(child);
+      }
     });
   },
 

test/jqLiteSpec.js

@@ -955,9 +955,14 @@ describe('jqLite', function() {
       expect(root.append('text')).toEqual(root);
       expect(root.html()).toEqual('text');
     });
-    it('should not append anything if parent node is not of type element', function() {
+    it('should append to document fragment', function() {
       var root = jqLite(document.createDocumentFragment());
       expect(root.append('<p>foo</p>')).toBe(root);
+      expect(root.children().length).toBe(1);
+    });
+    it('should not append anything if parent node is not of type element or docfrag', function() {
+      var root = jqLite('<p>some text node</p>').contents();
+      expect(root.append('<p>foo</p>')).toBe(root);
       expect(root.children().length).toBe(0);
     });
   });