Adds Fermi-LAT PSF data files
Adds loads script for PSF files
Adds unit tests for loading of PSF files
Adds a PSF study tutorial RST file
Adds tutorial plotting scripts for Fermi-LAT PSF study
Combined the 4 data irf files for Fermi PSF into one fits file
Updates Fermi Galactic Center data documentation for the correct IRF information
Merge pull request #191 from ellisowen/psf_data

Psf data