1) Added version guess to avoid warnings
2) At or around l 202 we used to check whether pat
was of type CircleDot or CirclePlus. I don't
know why. It gives wrong results when also
checking for CirclePlus
In f13b0bc0 we have introduced a hashing system that allows VEGAS to
note when the source code changes between integrations. However, this
did not work as it required recompiling vegas_m.o every time. Now this
is fixed.
