Fix memory leak in PandoraTranslator

[mark-grimes]

This fixes a memory leak of about 0.2 Mb/event in the pandora<->CMSSW translator. Plots below are for 0 pileup HGCal, since the leak is for each generator particle I don't think it's proportional to pileup (only have gen particles for the signal event).

@lgray says the check for integer charge is unnecessary so the original daughter particle address can used instead of creating a copy.
@lgray, can you check this PR is okay? As I understand it Pandora needs to be told explicitly about relationships, so the SetMCParentDaughterRelationship is still required even though the original particle has a pointer to the daughter, right?

Both plots are the memory retained by each module (top 25 only) after event execution, excluding the products they put in the event.
Before:

And after:

[cmsbuild]

A new Pull Request was created by @mark-grimes (Mark Grimes) for CMSSW_6_2_X_SLHC.

Fix memory leak in PandoraTranslator

It involves the following packages:

RecoParticleFlow/PandoraTranslator

The following packages do not have a category, yet:

RecoParticleFlow/PandoraTranslator

@cmsbuild, @nclopezo can you please review it and eventually sign? Thanks.
@mmarionncern, @bachtis, @lgray this is something you requested to watch as well.
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@fratnikov, @mark-grimes you are the release manager for this.
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[fratnikov]

please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: 01e2bda
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-9084/4679/summary.html

[fratnikov]

merge