Inconsistent regularizers #75
Description
The Laplace regularizers are currently inconsistent between 2d/3d in whether they allow padding or not, what the default option is (padding for 2d, no padding for LaplaceL23d, padding without an option to change it for FlatLaplaceL23d) and which versions are implemented (LaplaceL2norm only for 2d). Would it be possible to handle this in a consistent way? I'd also be interested in adding some variants to make it more complete (i.e. a LaplaceL23dnorm or a 1d variant of FlatLaplaceL23d so that one can deal with space-time separable 3d kernels out of the box).