modular installation options WRT openMM

[blakemertz]

Just compiled FFX with maven (thanks for making that relatively painless BTW). I'm interested in using FFX for MD simulations, and was wondering 1) what version of openMM is packaged with FFX and 2) is it possible to roll FFX with my own openMM installation? Asking because Debian now has openMM in the repos and I also have (counting on my fingers.....) 4 separate installations of openMM in distinct conda environments, so just trying to keep my sandboxes somewhat clean.