add bin/refcount_leak.py script to help detect leaks of UNO objects
add bin/refcount_leak.py script to help detect leaks of UNO objects

Initially this didn't help at all, but with some tweaks it now finds
the leaked ChartModel as the #3 and #4 printed stacks, with a very bad
score of 40.

Change-Id: I918bcb64bad0b9432bf2b670b03915836fb34a11

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core