RFR(S) 8240989: convert clhsdb "dumpheap" command from javascript to java

[Chris Plummer]

Hello,

Please review the following:
https://bugs.openjdk.java.net/browse/JDK-8240989
http://cr.openjdk.java.net/~cjplummer/8240989/webrev.01/

See the CR for details.

For the test I used ClhsdbField.java as a simple clhsdb template. To 
verify the dumped heap I added the call to printStackTraces(), which 
came from test/jdk/sun/tools/jhsdb/HeapDumpTest.java.

thanks,

Chris