Fix three small bugs with QMLListModel.

- $items was not initialized
- on insert this.$itemsChanged didn't pass the new value, which is
  needed internally
- on insert this.$itemsChanged would be emitted after rowsInserted,
  causing the new delegates to be created before all properties are
  in place.

src/qtcore.js

@@ -2446,11 +2446,12 @@ function QMLRepeater(meta) {
 function QMLListModel(meta) {
     QMLBaseObject.call(this, meta);
     var self = this,
-    firstItem = true;
+        firstItem = true;
 
     createSimpleProperty("int", this, "count");
     createSimpleProperty("list", this, "$items");
     this.$defaultProperty = "$items";
+    this.$items = [];
     this.$model = new JSItemModel();
     this.count = 0;
 
@@ -2488,8 +2489,8 @@ function QMLListModel(meta) {
     }
     this.insert = function(index, dict) {
         this.$items.splice(index, 0, dict);
+        this.$itemsChanged(this.$items);
         this.$model.rowsInserted(index, index+1);
-        this.$itemsChanged();
     }
     this.move = function(from, to, n) {
         var vals = this.$items.splice(from, n);