Fraction of friends for CPass1 now depends on coll system. (#378)

* Fraction of friends for CPass1 now depends on coll system.

- HI (PbPB/XeXE) --> 0.2
- pp --> 0.5
- pA/Ap --> 1.0

* Update main_recCPass1.C

DataProc/CPass1/main_recCPass1.C

@@ -105,7 +105,11 @@ void main_recCPass1(const char *filename="raw.root",Int_t nevents=-1, const char
   }
 
   // All friends
-  rec.SetFractionFriends(.2);
+  TString collSystem(gSystem->Getenv("ALIEN_JDL_LPMINTERACTIONTYPE"));
+  Float_t fractionFriends = 0.5;
+  if (collSystem == "PbPb" || collSystem == "XeXe") fractionFriends = 0.2;
+  else if (collSystem == "pA" || collSystem == "Ap") fractionFriends = 1.0;
+  rec.SetFractionFriends(fractionFriends);
 
  // AliReconstruction settings - hardwired MB trigger for calibration