Weird CUDA error when initializing with `wing_cut_pixels=None`

[gully]

I'm getting a weird GPU-specific error that I hadn't seen before. It only occurs when I initialize the SparseLogEmulator with wing_cut_pixels=None. It's expecting an integer, but should have an default when passed None, so it seems like a passthrough glitch. Meh! No matter, we have a workaround--- simply pass in your wingcut.