* Make names more uniform: FormFactorRipple1* where *=Box,Gauss,Lorentz
* Implementation through inheritance from ProfileRipple1
* Form factor in elongation direction x computed in namespace ripples

Enable Mac OS travis build

Change FormFactorDot. Suppress warnings. Edit FFCatalog.

In passing, eliminate a few other warnings too.

don't print threshold if data agree exactly

adapt GUI to change of FormFactorDot argument

Switch to XCode10.1 (Mac OS High Sierra) in Travis builds. By doing that we officially stop supporting Yosemite, El Capitan, and Sierra. Our Mac OS support now coincides with mantidproject.org.

Update Python 3.8 dll import and switch AppVeyor to it

Unify spelling in comments: "form factor" with blank.