VM1 to VM2: Recommend enhancements to the error reporting during migration

[mbarry]

Scenario:
      Run the VM2 Migration tool with "everything" selected".
       
Issue:
      Various warnings and error message don't provide enough detail to debug the issue being reported
      Specifically, portCategories(),  portProducts(),  portOrders() are areas that reported problems during my migration attempts where enhancement to messages was needed to hunt done the problems.

Solution:
      portCategories()
        line 866 change
          From
            vmError('Port Categories Xref unknow : ID '.$oldcategoryX['category_parent_id']);
          To
            vmError('Port Categories Xref unknown : Parent ID '.$oldcategoryX['category_parent_id'].' : Child ID '.$oldcategoryX['category_child_id']);

        line 876 change
          From
            vmError('Port Categories Xref unknow : ID '.$oldcategoryX['category_child_id']);
          To
            vmError('Port Categories Xref unknown : Child ID '.$oldcategoryX['category_child_id'].' : Parent ID '.$oldcategoryX['category_parent_id']);
           
      portProducts()
        line 1142 change
          From
            vmInfo('Coulndt find category for product, maybe just not in a category');
          To
            vmInfo('Couldnt find category for product, maybe just not in a category'.' : Product ID '.$product['product_id'].' Category checked : ID '.$cat);
         
      portOrders()
        line 1448 change
          From   
            vmWarn('Attention, order is pointing to deleted product (not found in the array of old products)');
          To
            vmWarn('Attention, order is pointing to deleted product (not found in the array of old products)'.' Order : ID '.$newId.' Product : ID '.$item['product_id']);

Affected files:
      administrator/components/com_virtuemart/helpers/migrator.php