Reviewed-by: sherman

6429910: (fc) FileChannel.lock() IOException: Bad file number, not AsynchronousCloseException
6814948: (fc) test/java/nio/channels/AsynchronousFileChannel/Lock.java failed intermittently
6822643: (fc) AsynchronousFileChannel.close does not invalidate FileLocks
Reviewed-by: sherman

Summary: Update for files that have been modified starting July 2008
Reviewed-by: ohair, tbell

Summary: Close channel and explicitly de-ref the mapped buffers before exit.
Reviewed-by: alanb

Summary: Should close the channel before delete the file
Reviewed-by: alanb