New features:

• experimental.XRayTransform: add .diagnostic_plot() to help verify specified geometries are correct.
• Add weighted XRT.

Bug fixes:

• ufuncs: correct operator shapes in functional API.
• ArgShiftRule(): correct shift parameter (in docs.)
• XRT tutorial: correct parallel beam specifiers. (Wasn't always parallel previously.)
• XRT: protect against out-of-bound reads, which would randomly cause crashes.