Backport changes from PR's 7574, 7785, 7936

[wulsin]

Backport of PR's #7574, #7785, and #7936.

[cmsbuild]

A new Pull Request was created by @wulsin (Wells Wulsin) for CMSSW_7_1_X.

Backport changes from PR's 7574, 7785, 7936

It involves the following packages:

SimG4Core/CustomPhysics

@cmsbuild, @civanch, @nclopezo, @mdhildreth can you please review it and eventually sign? Thanks.
@makortel 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.
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@Degano you are the release manager for this.
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[civanch]

please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: f54783e
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7944/2907/summary.html

[civanch]

+1

[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). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @Degano, @ktf, @smuzaffar

[davidlange6]

+1