HOWTO: Perform basic sanity checks on pythia in starsim

Pythia contains a subroutine PYTEST, which is a fully-functional pythia program.  PYTEST is configured out-of-the-box to test several standard model processes (and some BSM processes) at fixed-target, ISR, Fermilab and LHC energies.  To run under starsim:

starsim> gexec $STAR_LIB/libpythia{Version}.so
starsim> gexec $STAR_LIB/
starsim> call PYTEST(0) ** or 1 for more output

With pythia version 6_4_22, I have split the pytest subroutine from the main pythia source file and saved it under pystar-6.4.22.F.  This version of pytest runs several tests of pythia in processes which are relevant to RHIC physics:
1) QCD proccesses at CMS energies of 63, 200 and 500 GeV, 
2) Prompt photon production at CMS energies of 63, 200 and 500 GeV, 
3) W production at CMS energy of 500 GeV, and for fun...
4) An ep collider with 20 GeV electrons on 250 GeV protons.