clarify cookie comment.

laravel/cookie.php

@@ -92,7 +92,7 @@ class Cookie {
 		if ( ! is_null($value) and isset($value[40]) and $value[40] == '~')
 		{
 			// The hash signature and the cookie value are separated by a tilde
-			// character for convenience. To separate the hash and the contents
+			// character for convenience. To separate the hash and the payload
 			// we can simply expode on that character.
 			list($hash, $value) = explode('~', $value, 2);