Major updates:

• Support for Python 3 (mostly map, dict, and index fixes)
• Updated code comments for sphinx and readthedocs documentation
• Create setup.py install file
• Modify grism PSF shapes due to aperture shape
• Detector frames times based on ASIC microcode build 10
• Headers for DMS data
• PSF coefficient updates:
• coeffs based on module (SWA, SWB, LWA, LWB), rather than filter
• WFE drift coeff mods
• field-dependent coeff mods