[Rivet] Work plan

[Frank Siegert]

In the context of the Z finding discussion I actually checked what the 
InvMassFS does, and which analysis is using it:

CDF_2008_S7540469
D0_2008_S7662670
D0_2008_S7837160
D0_2008_S7863608
 - include it, but don't use it

D0_2001_S4674421
 - initialises it, but doesn't use it

(the above I have already cleaned up on SVN)

D0_2008_S6879055
 - uses it to check for existence of Z candidate
 - doesn't check for uniqueness, uses arbitrary l/l pair

CDF_2008_S7541902
 - uses it for W decay products
 - doesn't check for uniqueness, uses arbitrary l/nu pair

CDF_2008_S8095620
 - uses it for Z decay products
 - doesn't check for uniqueness, uses arbitrary l/l pair

I don't believe that any analysis should actually use an arbitrary pair. I 
guess, either they use all of the found candidates, or they reject an 
event without unique candidate?

Frank