update to PUPPI;speedup, low PU corr

[cmsbuild]

This update contains the code for PUPPI v9

Biggest updates are a speedup (and more speedup possibility in the future) and fixes for the low PU behavior.

Final v9 version will be ready after tuning is performed with the new HCAL/ECAL reconstruction fixes and new constants are committed.
Automatically ported from CMSSW_7_6_X #11671 (original by @nhanvtran).

[cmsbuild]

A new Pull Request was created by @cmsbuild for CMSSW_8_0_X.

update to PUPPI;speedup, low PU corr

It involves the following packages:

CommonTools/PileupAlgos

@cmsbuild, @cvuosalo, @vadler, @monttj, @slava77 can you please review it and eventually sign? Thanks.
@ahinzmann, @jdolen, @rappoccio 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

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/9085/console

[cmsbuild]

Pull request #11884 was updated. @cmsbuild, @cvuosalo, @vadler, @monttj, @slava77 can you please check and sign again.

[cmsbuild]

+1
Tested at: bca6373
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11884/9085/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11884/9085/summary.html

[slava77]

+1

for #11884 bca6373

• the same changes as in 76X in update to PUPPI;speedup, low PU corr #11671
• jenkins tests pass and comparisons with baseline show no differences
• see notes in update to PUPPI;speedup, low PU corr #11671 for more details: timing decreases, the number of puppi jets increases slightly