prevent PAT photon iso variables from overwriting Reco ones

[gzevi]

This is a different solution, suggested by @monttj and @lgray in #7761, to the issue of pat::Photon variables having the same name as reco::Photon variables.
Instead of renaming PAT variables (which would introduce an inconsistency between different PAT objects), we force PAT variables to return the corresponding Reco values.
This commit undoes the changes of #7764, which was not approved.
This commit is also backported to 74X in #8494

[cmsbuild]

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

prevent PAT photon iso variables from overwriting Reco ones

It involves the following packages:

DataFormats/PatCandidates

@cmsbuild, @vadler, @nclopezo, @monttj can you please review it and eventually sign? Thanks.
You can sign-off by replying to this message having '+1' in the first line of your reply.
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@nclopezo you are the release manager for this.
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[ghost]

please test

[cmsbuild]

The tests are being triggered in jenkins.

[Dr15Jones]

Note: when we switch to ROOT6 you'll be able to use the C++11 mechanism of saying you want to use a function for the base class:

   using reco::Photon::chargedHadronIso;

[cmsbuild]

-1

Tested at: bf7130f
I found errors in the following unit tests:

---> test runtestPhysicsToolsPatAlgos had ERRORS

you can see the results of the tests here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-8493/3753/summary.html

[monttj]

+1

[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