Added support for histories with identical names

Was informed of this by your colleague Ron. I didn't read the note saying this was unmaintained, so feel free to reject and I'll make the PR against GVL (though you may wish to consider keeping this separate and using submodules to load in GVL)

What this addition does is handle identically named histories by append `-HIST_ID` to the end, thereby disambiguating them and allowing folder traversal. I'll add in dataset disambig once I figure out all of that. Cheers