[DPP-84] Possible Memory Leak on Supervisor

[qnikst]

[Imported from JIRA. Reported by Roman Gonzalez @roman) as DPP-84 on 2013-12-09 19:15:36]
When running addChild/removeChild in a loop using the Supervisor API, we noticed a memory leak. I don't know if this is related to #DPP-72.

We have tried to replace the StateT monad being used in ManagedProcess to be Strict, and created a NFData instance for the Supervisor State, and that doesn't seem to stop the leak. We will add more ps files with profiling as we go.

Here is the code we are using for the test:

https://gist.github.com/roman/7878922

Attached is one ps