eblur/newdust: Python extinction and scattering halo calculations for astrophysical particulates

Latest version of Corrales et al. (2016, 2023) extinction and scattering halo calculation tool for astrophysical particulates (previously github.com/eblur/dust). This code has been updated 2016-2022 to write and read FITS table data for easy recall of calculations, make fake images of X-ray dust scattering halos and echoes, and was updated in Summer 2022 to utilize the astropy.units library to easily change the units of input quantities for calcuation.