[Rivet] Time for Rivet 2.5.3?

[Andy Buckley]

Hi Riveters,

I merged all the pending contrib analyses into the Rivet 2.5.x branch 
last week, and along with a few other infrastructure improvements and 
bugfixes this feels to me like critical mass for the next patch release, 
2.5.3.

I think the automatic build & validation system is maybe having trouble 
at the moment (Holger?), but once that is running successfully on the 
branch head I suggest that I just tag & release the thing: any 
objections / last requests?

Cheers,
Andy

PS. From here I hope that we can get the main features for 2.6.0 done 
and ready for release in January, and hopefully the next v3 beta will be 
available for Christmas, with a full release not too long into 2017.

-- 
Dr Andy Buckley, Lecturer / Royal Society University Research Fellow
Particle Physics Expt Group, University of Glasgow