Changed TrackWithVertexRefSelector to a stream module.

[Dr15Jones]

Static analysis and helgrind showed it is safe to convert this
module to a stream module. Thread performance analysis showed
this conversion is needed for efficient threading.
To do the conversion, I introduced ObjectSelectorStream templated
base class.

[cmsbuild]

A new Pull Request was created by @Dr15Jones (Chris Jones) for CMSSW_7_2_X.

Changed TrackWithVertexRefSelector to a stream module.

It involves the following packages:

CommonTools/RecoAlgos
CommonTools/UtilAlgos

@nclopezo, @monttj, @cmsbuild, @StoyanStoynev, @slava77, @vadler, @Degano can you please review it and eventually sign? Thanks.
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[Dr15Jones]

Same as #4085 for CMSSW_7_2

[cmsbuild]

+1
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-4091/47/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-4091/47/summary.html

[StoyanStoynev]

+1
Some difference in Jenkins (1 DQM plot in wf 4.53) prompted further checks.
Tested 6d59975 in CMSSW_7_2_X_2014-06-05-0200.
1000 events with wf 4.53 showed difference in phi-angle plots (a group of SuperClusterActivityFilter and PixelMatchFilter histograms) like these

.
Further checks with 1-2k events with photon/electron guns and ttbar/QCD wf showed a couple of cases with a small difference in SuperClusterActivityFilter (same phi-angle feature at phi~0). Likely a numerical instability. No other differences.

[Dr15Jones]

@vadler, @Degano ping?

[Dr15Jones]

@vadler, @Degano ping?

[monttj]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_2_X IBs unless changes (tests are also fine).