Merge pull request #76 from NativeScript/zhecheva/flexbox-order

FlexboxLayout exposes a method for clearing the orders cache

android/widgets/src/main/java/org/nativescript/widgets/FlexboxLayout.java

@@ -518,6 +518,15 @@ public class FlexboxLayout extends ViewGroup {
         return false;
     }
 
+    /**
+    * Invalidates the cache of the orders so that they are recalculated. 
+    */
+    public void invalidateOrdersCache() {
+        if (this.mOrderCache != null) {
+            this.mOrderCache.clear();
+        }
+    }
+
     /**
      * Sub method for {@link #onMeasure(int, int)}, when the main axis direction is horizontal
      * (either left to right or right to left).