new_table in astropy pyfits is deprecated so now I use BinTableHDU.from_columns to do the same thing
added try except so writing the truth catalog works with astropy pyfits or older pyfits. this is sort of to make sure it still works on the cosmos machines until I update my astropy version
added magnification to what prints when a galaxy can't be drawn. this was mostly for debugging, but doesn't hurt in any way. mostly it's irrelevant as long as everything is running properly.
Merge branch 'master' into im3shape-driver