Add missing header files.
Add King profile PSF unit test, correctly normalize fixed delta_max PSF, and automatically detected King profile PSF upon IRF loading.

A unit test was added to verify that the King profile PSF is normalized correctly. For this purpose a King profile PSF calibration was inserted in slot 2 (bcf/000002) of the calibration database.

As the delta_max has been fixed to 0.7 degrees, the King profile PSF now returns 0 for delta angles larger than 0.7 deg. Furthermore, the PSF is normalized so that the integral from 0 to 0.7 deg gives 1. In that way we assure that the PSF integral is always 1.

The GCTAResponse::load_psf method now automatically detected the King profile PSF. Also, the load method now allow specification of a FITS file as the IRF name.
Limit delta in mc() method to r_max.
Add PSF simulation test script.