Changes done in multicart files for working in PHP 5.4

1.  session_register() and session_unregister() are deprecated

    For this following changes are done : 
      session_register() function is put in a condition:

      if(function_exists('session_register'))
        {
	   session_register();
		
        }

    Similarly for session_unregister()
	if(function_exists('session_unregister'))
        {
	   session_unregister();
        }

  These are used for session_register() and session_unregister()

It was the solution for following bugs :
 
1) Bug25409  :-php 5.4 compatibility>>User registration>>Registration doesn't require user approval from admin. User should be automatically logged in. But this is not working properly
2) Bug25411 :- php 5.4 compatibility>>Getting a blank page when user click 'add to cart' button in the frontend
3) Bug 25419 :- php 5.4 compatibility>>Seller>>When the user login as a seller, first he/she is directed to a blank page and when back button of browser is clicked, user will be logged in


2. Put exit(); after each header redirect code

    header("Location:" . SITE_URL . "/login.php?action=checkout");
    exit;

   1. Bug 25421 :- php 5.4 compatibility>>Payment gateways are not working


3. sample.csv is updated fror the below bug

Bug25417 : -php 5.4 compatibility>>Bulk product upload not working properly in both admin and seller side.