GIGAQBX TS paper experiments for urchins use a large amount of memory

I'm unable to run the cost model for the urchin \gamma_{10} on porter (which has 64 GB of RAM). It starts to thrash before the refinement of the geometry is completed. I have to use dunkel (which appears to have 4x the memory as porter) to run the cost model. Perhaps this is worth investigating as it is possible this is related to the memory leaks in pytential (#131 (closed)).

(Will provide an example soon.)