HIJING needs HIPYSET

[preghenella]

Hello @ktf,

it seems to me that this HIJING package misses a piece of software which is normally needed to run it properly. Quoting from http://ntc0.lbl.gov/~xnwang/hijing/

To save compiling time, JETSET.7.2 is not included in HIJING. To meet some specific needs of HIJING, JETSET.72 has been modified and renamed as HIPYSET. One should link HIJING with HIPYSET and the main program

The simplest solution I could imagine would be to take HIPYSET code from AliRoot
https://github.com/alisw/AliRoot/tree/master/HIJING/hipyset1_35
add it to this repository and add the source files to the list of SOURCES in CMakeLists.txt.

I have made myself this exercise in my fork and I manage to run HIJING fine
preghenella@ce95fad
preghenella@06e9e1d

Another approach could be to have HIPYSET as a separate package, introduce a dependency in HIJING and make sure HIJING links it.

Roberto