Add ability to run an input .hddm file over a run range

[markdalton]

Currently generated events provided as an input .hddm file can only be simulated for a single run, not a run range.

[T-Britton]

This will be done soon. I have a couple things first but this is nearing top priority

[T-Britton]

this ended up being fairly non trivial. hampered in part by a python 2 v 3 transition.

[jrstevenjlab]

I see. There is renewed interest in having flexibility for those developing new generators to be able to pass them into MCWrapper, so it would be good to resolve this.