add options to HLTMuonDimuonL3Filter

[gpetruc]

make the filter a bit more flexible, so that it can be used to build more complex conditions.

• allow requiring multiple pairs per event
• allow to have PreviousCandTag pointing to a L3 filter instead of a L2 one

the default values of the parameters, set in fillDescriptions, don't change the current behaviour

will be used in a proposal to reduce drastically the rate of HLT_TripleMu_5_3_3_v2 by adding Δz and dilepton mass cuts

[cmsbuild]

A new Pull Request was created by @gpetruc (Giovanni Petrucciani) for CMSSW_8_1_X.

It involves the following packages:

HLTrigger/Muon

@perrotta, @cmsbuild, @silviodonato, @Martin-Grunewald, @fwyzard, @davidlange6 can you please review it and eventually sign? Thanks.
@battibass, @abbiendi, @jhgoh, @Martin-Grunewald, @HuguesBrun, @trocino this is something you requested to watch as well.
@slava77, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[Martin-Grunewald]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/15029/console

[cmsbuild]

+1
Tested at: bba4b54
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15770/15029/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15770/15029/summary.html

[Martin-Grunewald]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_1_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @smuzaffar

[davidlange6]

+1