Code Review Request for 6578042

[Darryl Mocek]

Hello.  Please review this patch to fix Bug #6578042 
(System.clearProperty() throws ClassCastException if property value 
isn't a String).  The issue is that through the Hashtable methods, it's 
possible to add a Property which isn't a String and set it through 
System.setProperties.  clearProperty cast the returned removed object as 
a String, even if it wasn't a String.  Test case provided.

Webrev: http://cr.openjdk.java.net/~sherman/darryl/6578042/webrev
Thanks,
Darryl