New steps for HI muon RegIt

[echapon]

Two steps are added to the regional iterative tracking (RegIt) for heavy ion muons: the detached triplet step, and the "muon-seeded step", based on the equivalent step from pp iterative tracking.
This PR is a 75X backport of #10952

[cmsbuild]

A new Pull Request was created by @echapon (Emilien Chapon) for CMSSW_7_5_X.

New steps for HI muon RegIt

It involves the following packages:

RecoHI/HiMuonAlgos
RecoHI/HiTracking

@cmsbuild, @cvuosalo, @slava77 can you please review it and eventually sign? Thanks.
@MiheeJo, @jazzitup, @richard-cms, @yenjie, @kurtejung, @istaslis, @mandrenguyen, @dgulhan, @yetkinyilmaz this is something you requested to watch as well.
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@Degano you are the release manager for this.
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[slava77]

@cmsbuild please test

@echapon please post some slides to performance changes, preferably showing both physics effects (efficiencies/fake rates) and the technical performance (CPU). For the physics side, I suppose the change was discussed in a meeting already (if so, a link would be nice)

[slava77]

nevermind, slides are available in #10952

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: c616f47
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-10953/7669/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-10953/7669/summary.html

[cvuosalo]

+1

For #10953 c616f47

For Heavy Ion muons, adding regional iterative tracking and detached triplet and muon-seeded steps. #10952 is the 76X version of this PR, and it has already been approved by Reco.

The code changes are satisfactory. Jenkins tests against baseline CMSSW_7_5_X_2015-08-26-1100 show some very tiny, insignificant differences for HI workflow 140.53. See #10952 for details about timing changes.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_5_X IBs once checked with relvals in the development release cycle of CMSSW (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @Degano, @smuzaffar