Fix Grid and Escalator accessing of SubPartArguments

This patch removes an extra static method from Escalator and makes Grid
and Escalator call SubPartArguments create(String) method directly.

Change-Id: I6825bc89540c6183a8fddeded8133fb7ef8e23f1

client/src/com/vaadin/client/widgets/Escalator.java

@@ -6653,7 +6653,7 @@ public class Escalator extends Widget implements RequiresResize,
     @Override
     @SuppressWarnings("deprecation")
     public com.google.gwt.user.client.Element getSubPartElement(String subPart) {
-        SubPartArguments args = parseSubPartArguments(subPart);
+        SubPartArguments args = SubPartArguments.create(subPart);
 
         Element tableStructureElement = getSubPartElementTableStructure(args);
         if (tableStructureElement != null) {
@@ -6816,8 +6816,4 @@ public class Escalator extends Widget implements RequiresResize,
     private String getSubPartNameSpacer(Element subElement) {
         return body.spacerContainer.getSubPartName(subElement);
     }
-
-    public static SubPartArguments parseSubPartArguments(String subPart) {
-        return SubPartArguments.create(subPart);
-    }
 }

client/src/com/vaadin/client/widgets/Grid.java

@@ -6513,7 +6513,7 @@ public class Grid<T> extends ResizeComposite implements
             return DOM.asOld(escalatorElement);
         }
 
-        SubPartArguments args = Escalator.parseSubPartArguments(subPart);
+        SubPartArguments args = SubPartArguments.create(subPart);
 
         Element editor = getSubPartElementEditor(args);
         if (editor != null) {