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

Including updated tests.
1. I think it didn't work with BSpline2d because the "eval" method there isn't declared const.
2. It may not be reasonable to require that the "evaluate" method of model fitting algorithms doesn't change the object, e.g. if certain calculations are delayed. (And I don't see what the benefit would be.)
3. For the parameter, what's the point of declaring it as const if it's passed by value?