Description:
------------
This is a reactivation of bug 28442; that bug shows as "fixed/closed", but the issue still repros. 

We need to be able to redefine static members of classes (including constants), and set them independently.

Reproduce code:
---------------
class ClassA
{
   private  static   $cn;

   public static function setName( $cn )
   {
      self::$cn   = $cn;
   }

   public static function  getName( )
   {
      return self::$cn;
   }
}

class ClassB extends ClassA
{
   private  static   $cn; // with or without this, result is the same
}

ClassA::setName( 'AAA' );
ClassB::setName( 'BBB' );

print( ClassA::getName() . "\n" ); // prints 'BBB'
print( ClassB::getName() . "\n" ); // prints 'BBB'


Expected result:
----------------
Result should read "AAA BBB"

Actual result:
--------------
Result actually reads "BBB BBB"