Updated the DEIMOS 1200G, 830G, and 600ZD archival sensfuncs to used data with redder wavelength coverage.
Refactored the way the stitched sensfuncs are created by creating new utility functions in a stitchutils.py file.
Created a new stitch_sf_polyfit that is smarter about joining the sensfuncs and creating a wavelength grid. But unfortunately I ran out of time to update 900ZD and 1200B to use it, so there's still a a stitch_polyfit_old function
Update the dev_algorithm utilities to work with the new code and new PypeIt version.
stitch_polyfit_oldfunction