sync ME2pythia.f with 4_1_9 and add Z2star tuning

Changes needed by FSQ for producing Madgraph sample with 2010 conditions
- ME2pythia.f updated to revision 1.15 of old CVS repository. Fix an infinite loop issue for NJETS=4 and it is now synched with 4_1_X head
- configuration for Z2star tuning added