OMPI version configuration

[wckzhang]

Need to add easier way to run collectives on different OMPI versions (They have different numbers of algorithms for example)

This will need a config file change specifying OMPI version, or at least a parameter in run_and_analyze, and separate collective_jobs directories for each ompi version we care about. I'll make one for 3.x.x, 4.x.x, 5.x.x, and master.

I toyed around with the idea of creating separate branches for each, but the amount of backporting would be stupid, so not going to do that.