Extract SF_Key, _Coupling and _Lorentz
... i.e. move them into separate files, in order to make the
Splitting_Function_Base
files less bloated.
This has been done in both CSSHOWER++
and MCATNLO
. I also added a comment to document the unintuitive Filler_Getter
idiom used to initialize splitting function couplings.
Edited by Enrico Bothmann