Did huge makeover of uvis_contam.py so that it is better organized. Improved ptsrc_photom_uvis.py so that it is more flexible over flts. Wrote run_lacosmic_v2.py to perform IRAF's LACosmic (lacos_im.cl) task over flts. The python-based run_lacosmic_v1.py is faster, but it garbles up headers.