Directions or FSS2015 on minimal usage of make3FGLxml.py script to produce a model for LAT likelihood analysis:
	Download make3FGLxml.py and the README file from the user contributed scripts page at the FSSC http://fermi.gsfc.nasa.gov/ssc/data/analysis/user/
	make the script executable, in the directory you downloaded it to:
		chmod u+x make3FGLxml.py
	then either 1) move it to one of the directories defined in the PATH environment variable or 2) put the script (or a link to it) in the directory you're going to be working in
		if 1) after you move it open a new terminal and you'll be able to type make3FGLxml.py on the command line and use it like any other executable
		if 2) when you want to use it you'll have to type ./make3FGLxml.py followed by the commands
	the minimal arguments you need to give it are the 3FGL catalog (or XML) file and your event file
		suppose the catalog is stored in /mydata/mycatalogs/gll_psc_v16.fits, the minimal usage would then be:
			make3FGLxml.py /mydata/mycatalogs/gll_psc_v16.fits myevents.fits
		however, the defaults won't find the correct Galactic and isotropic diffuse file paths (sorry about that) so you'll want to specify those too...as well as the path to the isotropic template
		to see all the options available, simply type make3FGLxml.py -h