Update of MET significance tuning for Phys14 samples

[mmarionncern]

Same as #8396 for 75X, replace #8398 which was incorrectly assigned to 74X

[cmsbuild]

A new Pull Request was created by @mmarionncern for CMSSW_7_5_X.

Update of MET significance tuning for Phys14 samples

It involves the following packages:

RecoMET/METAlgorithms
RecoMET/METProducers

@cmsbuild, @cvuosalo, @nclopezo, @slava77 can you please review it and eventually sign? Thanks.
@TaiSakuma, @ahinzmann, @jdolen, @nhanvtran, @schoef, @mariadalfonso this is something you requested to watch as well.
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[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: 4d4fa2a
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-8402/3608/summary.html

[cvuosalo]

+1

For #8402 4d4fa2a

Corrected the sumpT used for MET significance, which is not computed by default in the standard reco sequences. This PR is the same as #8396 for 74X, which was already approved by Reco.

The code changes are satisfactory, and Jenkins tests against baseline CMSSW_7_5_X_2015-03-18-2300 show no significant differences, as expected. There is a RelVal error in the baseline IB, but it did not impair the Jenkins tests.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_5_X IBs unless changes (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @nclopezo, @ktf, @smuzaffar

[davidlange6]

+1