[Ifeffit] Larch 0.9.61

Hi Folks, It's only been a few days, but there were some fairly important bugs and misfeatures found with Larch 0.9.60. Rather than wait, these have mostly been fixed (details at https://github.com/xraypy/xraylarch/releases/tag/0.9.61). You can either update the code yourself with `pip install --upgrade xraylarch`, with the binary installer, or by allowing XAS Viewer to run its updater. Bug reports, comments, and suggestions are always welcome. --Matt