Revisit GSAS-II License

[briantoby]

One ESRF user has questioned possible limitations related to the GSAS-II license and FAIR implications (BHT: see e-mails dated 7/12/24 & 7/123/25 on "Collaboration around GSAS"). We want the license to be as open as makes sense, so a review of licensing options and survey of problems created by our current license sounds like a good idea.