This is the Refcount Balancer.  See
https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Refcount_tracing_and_balancing
for documentation.

Note that the `fix_stacks.py` script is used in several other places in the
repository.

Previous CVS history for the perl scripts is available at:
http://www.mozilla.org/webtools/bonsai/cvslog.cgi?file=mozilla-org/html/performance/find-leakers.pl&rev=&root=/cvsroot/
http://www.mozilla.org/webtools/bonsai/cvslog.cgi?file=mozilla-org/html/performance/make-tree.pl&rev=&root=/cvsroot/