Remove depricated helper

Get rid of this experimental visualvm helper

Signed-off-by: Francis Giraldeau <francis.giraldeau@gmail.com>
Add HeapDump for memory profiling

The HeapDump allows to save the heap layout in HPROF format, that can be opened
in Eclipse Memory Analyzer. Just add this to the code when the heap dump is desired:

  HeapDump.dumpHeap("tracesync.hprof", true);

Signed-off-by: Francis Giraldeau <francis.giraldeau@gmail.com>