Re-added B-spline transformation for non-linear RT alignment in MapAlignerIdentification

Including updated tests.
I've removed them because they were not used anywhere and didn't seem necessary. There are a number of methods of the eol-bspline library that could potentially be useful at some point, but weren't wrapped. I think that these are in the same category.
("nX" I previously folded into "getParameters", which I later removed by request. The caller can easily check how many points it passes to the B-spline fitter, so there's no need for the method.
"coefficient" seems like an internal of the B-spline fit, which I didn't think made sense to expose in the wrapper.)