Add Spherical curvature distortion transformation

[bogovicj]

This PR adds a SphericalCurvatureDistortionTransform that can serve to model a particular kind of distortion in optical systems.

This example code:

final int numDimensions = 2;
final int dimensionToTransform = 1;
final double radiusOfCurvature = 250;
final SphericalCurvatureDistortionTransform tform = new SphericalCurvatureDistortionTransform(
		numDimensions,
		dimensionToTransform,
		radiusOfCurvature);

final ArrayImg<UnsignedByteType, ByteArray> img = ArrayImgs.unsignedBytes(256,256);
img.view().interval(Intervals.createMinMax(36,128,164,164)).forEach( x -> x.set(255) );

final RandomAccessibleIntervalView<UnsignedByteType> imgTform = RealViews.transform(
	img.view()
		.extend(Extension.zero())
		.interpolate(Interpolation.nLinear()),
	tform).realView().raster().view().interval(img);

ImageJFunctions.show(img, "toy tile");
ImageJFunctions.show(imgTform, "toy tile distorted");

produces this output: