pbp indexer - y0 not added in grid and units for diffty not matching distance

[jonwright]

Around line 2000 in point_by_point:
"""
nlo = np.floor((self.ybincens.min()) / self.ystep).astype(int)
nhi = np.ceil((self.ybincens.max()) / self.ystep).astype(int)

    rng = range(nlo, nhi + 1, gridstep)

"""
It needs to subtract y0 if there was one.

Also noted: the distance correction in get_local_gv assumes dty and distance have the same units. This is harder to fix automagically unless everything comes with units.

[jonwright]

Also the indexing loglevel does not work when changed. Something about the multiprocessing pool and global state perhaps. No idea how to fix that.

[jadball]

For the first issue: here's the commit to blame: 32dfd94

It seems I was correcting a y0 bug for a dataset with a big y0 by modifying the code in two places - I remember things definitely got better after the bug fix, but I suspect the second fix wasn't needed. To me this raises deeper questions about how the geometry.dty_to_dtyi function works/should work. TODO after Christmas for sure!

[jadball]

I think the underlying problem is that we assume that a perfectly aligned diffractometer would have a y0 value of 0?