[Rivet] Merging aida files

[Gavin Hesketh]

Hello,
I was looking for a way to merge aida files from different runs into 
one. The way I can up with is:

aida2root XX.adia
merge the root files, adding histograms & normalising each as needed
root2flat XX.root
flat2aida XX.dat

If there is a better way, I'd like to know! Anyway, this turned up what 
seems to be a bug in the root2flat script, line 152:
         i = ii + 1

I have to comment out the "+ 1" to get the right output.

cheers,
	Gavin