[Rivet] Bugfix release 1.2.1

[Frank Siegert]

I have just committed ALEPH_2004 which is a very nice update to analyses 
like ALEPH_1996 and DELPHI_1996 I believe (especially so with respect to 
jet rates).

While implementing this, I startet wondering about the 1996 analyses in 
Rivet: They use charged particles as input for the event shapes, while the 
ALEPH_2004 paper explicitely uses charged+neutral. Has this really changed 
from 1996 to 2004, or are these analyses doing the wrong thing?

Frank