6614052: jhat fails to read heap dump > 2GB.
Summary: Modified the jhat code to use long for unsigned int. This is a forward port of changes from Kevin Walls.
Reviewed-by: jjh
6576763: Thread constructors throw undocumented NPE for null name
Summary: update javadoc to specify NPE as well as fix minor bug in implementation.
Reviewed-by: alanb