RectifyParams.normalize(): Disable normalizing offset, fix tau normalization
RectifyParams: New method from_steps() and static method median()
ImageTiling.tile_to_imgxy(): Add support for randomized origin perturbation
autorectify_cv(): Construct lensmatrix from holematrix, enable lensmatrix->RectifyParams transformation, return median RectifyParams

At this point, autorectification finally starts to produce roughly meaningful results, but there is still a lot of work to be done, the results are rather imprecise.