PR# 11244 Large memory leak in estudio from repeatedly clicking on cluster

Estudio still has a large memory leak (but not a huge one).

To reproduce:
Note heap size via "pmap PROCESS_ID | fgrep -i heap".
In Clusters window, repeatedly click on a cluster (I used my root cluster,
which has about 15 classes, two of which are in the system).
Heap size keeps growing about 100 KB per click on average, though of course
it is not at all linear since there are big steps up when a big chunk of new
memory is allocated.

I suspect that something is being held onto too long, rather than a true leak
where the pointer to the memory gets lost so that it can never be returned.

Please add this to the list as a "**" item.