GPU 6 equation model + Phase change

[sbryngelson]

Full 6 equation model with phase change on GPUs.

[mrodrig6]

I made progress, phase + master + hypo are merged and pushed to the phasechange branch.

@js-spratt Needs to check the hypo merger within the phasechange branch. grep -iRn J-S the files to see the TODO items that I did in the merger

[sbryngelson]

This is a project, so I will close its "issue".