cleaned out PPi0Example. Needed for GH1 testing.
added GHistMamager with GLinkedHist.
Every linked hist will be saved automaticly in the end.
There is an optional Bool_t in the constructor of GLinkedHist to switch it of.
first idea of scaler corrected histogram.
finished scaler correction in GScaCorHist.
GScaCorHist fully functional now.
first idea of GBGSubHist.