#4 memory leak

[Richard Liston]

After running Landmarks Demo for a few days straight I
started seeing this:

Exception in thread "Thread-2077234"
java.lang.OutOfMemoryError: Java heap space

These messages seem to appear right after the periodic
event or numnodes or numneighbors events print out in
the network events window, but not the landmarksperf
event. Stopping and restarting Landmarks Demo doesn't
help. It starts printing again right away.