Implementing Asymmetric CSD for Dipy

[Remi-Gau]

Submitted by Daniel Moyer

Recently some authors (not me!) created this awesome asymmetric local model for diffusion: paper (paywalled). Unfortunately, they haven't released code, and even if they do...it won't fit into our current dipy pipelines. If people are interested, we can try and implement it. It doesn't look too hard, so if there's interest, let's get into it!