Adds a new Action on the selected Page's index
If no index is given it is added in the first available index
  overload 1:
                        
Page:newAction()  
  | Method Property |  Fluent Description |  Representation | 
 | Return Value |  an Action |     |    
 
        overload 2:
                        
Page:newAction(index)  
  | Method Property |  Fluent Description |  Representation | 
 | index accepts |  an Integer |     |    
| Return Value |  an Action |     |