[Rivet] Work for Rivet 2.4.0 release: call for contributions!

[Frank Siegert]

> Holger
>   CMS_2013_I1122847  (missing since 2.3.0 cf. Xavier's email)
>   D0_2000_I503361.tar.gz
  --> cf. the clarifications asked for in the submission thread. I
think if this cannot be clarified, we don't have to hold the release
for this one analysis.

Cheers,
Frank