fixed Browninan motion kern (doesnt seem to have a unittest?)
some simplification of the psi2_statistics in rbf
auto_scale
more work on visualize
more fun with vizualize
manual merge in plot_latent
more manual merging
Reverting last change
rbf computation of psi2 now works if there's only one datum
improved stability of sparse GP computations

Specifically in computing dL_dKmm
comments only
Merge branch 'mrd' into devel
Merge branch 'devel' into mrd
added bgplvm_simulation on same simulation