PU weighting (71x)

[jpavel]

Backport of #4131. (for completeness, 70x request is #4508)

Adds option to run weighted isolation, no changes expected in default running. All documentation in #4131

@bachtis, @monttj

[cmsbuild]

A new Pull Request was created by @jpavel (Pavel Jez) for CMSSW_7_1_X.

PU weighting (71x)

It involves the following packages:

CommonTools/ParticleFlow
RecoParticleFlow/Configuration

@nclopezo, @monttj, @cmsbuild, @StoyanStoynev, @slava77, @vadler, @Degano can you please review it and eventually sign? Thanks.
@bachtis, @lgray this is something you requested to watch as well.
You can sign-off by replying to this message having '+1' in the first line of your reply.
You can reject by replying to this message having '-1' in the first line of your reply.
@nclopezo, @ktf you are the release manager for this.
You can merge this pull request by typing 'merge' in the first line of your comment.

[monttj]

+1

[cmsbuild]

+1
Tested at: 6affdf0
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-4509/1786/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-4509/1786/summary.html

[StoyanStoynev]

+1
Based on jenkins and the fact this PR is identical to #4131 (for 72X).
I did check that I can run the new customise option with the PR.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_1_X IBs unless changes (tests are also fine). @nclopezo, @ktf can you please take care of it?