Simulation Setup Wizard

[dwhswenson]

This will add an interactive setup wizard to the OPS CLI. The wizard will guide users through the process of setting up simulation objects to use in a simulation, and will save the created objects to a SimStore database (hopefully with a little fun along the way). This PR will have support for a wizard to do flexible-length TPS simulation using an OpenMM engine and MDTraj CVs (tested by stepping through the setup for alanine dipeptide).

[dwhswenson]

It looks like this needs to wait on the release of OPS 1.5

[dwhswenson]

close/open to trigger CI

[dwhswenson]

This is ready for review and comment. I will leave it open for at least 72 hours, merging no earlier than Tue 27 Jul 15:00 GMT (11:00 my local).

This is a huge PR, and only intended to be a first draft of the OPS Wizard. For now, it gives some basic options for 2-state TPS. The API for this is very much in flux, and will probably be largely rewritten after I finish #43. I started out by writing the wizard before the file parsing, but in the end, it will make much more sense for the wizard to re-use a subset of the things in the file parsing.

[sroet]

I am not familiar enough to fully grasp all the intricacies of the implementation, but I reviewed it looking for sub-optimal code/behviour. Feel free to ignore

[dwhswenson]

Thanks for looking this (huge) PR over, @sroet! This and #43 represent a couple of really big additions, and since they add whole new subsystems, I sort of needed to add it all in one huge PR (I couldn't tell if any of it worked until I had written all of it.)

Merging this one in now.