ForceField XML Files and Future Spirints for ForceField Class

[umesh-timalsina]

Now #186 is merged, the next step would be collect as many XML Files as possible. Infact, the next step should be the ability to convert standard XML files from other packages and convert them to topology in a standard fashion. Please do not hesitate to send your XML files to me. https://gist.github.com/umesh-timalsina/952c9974882d70fee4b7619ba6438c93

[rsdefever]

See here:

https://github.com/rsdefever/antefoyer/tree/master/antefoyer/xml

[umesh-timalsina]

Thanks @rsdefever and @ahy3nz for contributing or pointing out your xmls. To close #191, we need the following:

1. Write our XML converters <- Foyer, OpenMM etc...->: Convert a topology XML into the XML format used by various other packages and viceversa. (I would like this to be setup as a function as well as a command line feature).
2. A minimalist mapping that looks at Foyer's Force-Filed class and what changes are necessary in topology ForceField class to make it the ForceFiled class in foyer.

[umesh-timalsina]

This issue warrants some insights from @mosdef-hub/mosdef-contributors