Significant changes

Code to allow for mosaicing multiple detectors into a single reduction. This is now the default for Gemini GMOS and improves stability of wavelength calibration.
Introduces pypeit_parse_calib_id script
Refactored manual extraction
Update for LDT/DeVeny including support for binned data, use_header for reading arc lamps used from frames, and reid_arxiv templates for three additional gratings.
Slurps in and uses slitmask design for Keck/LRIS (limited usage)
Significant improvements in 2D coadding.
Scripts to explore the noise residuals in PypeIt

Datamodel changes and algorithmic improvements

Improved performance of L.A. Cosmic implementation
Now uses stars in alignment boxes for default calculation of slitmask offsets in DEIMOS reductions.
2D wavelength calibration image now added to MasterFlat output
Improved treatment of saturation.
Dark counts used for calculating the shot noise now includes measured dark images if provided.
Include sky model in 2nd pass of global sky subtraction (not for IR redux).
Skymask is now computed also for the maskdef_extract objects.
Added dedicated fwhm and boxcar_radius for maskdef_extract objects.
Added pypeit_version to the pypeit file header.
Set DEIMOS find_fwhm default to 0.8" in binned pixels.
Added row-dependent pattern-noise calculation for KCWI