Reunify p sim hit map

[davidlange6]

Tim's changes in PR
but with on PSimHitMap class instead of two that differ by a few lines (and one that isn't used)

[cmsbuild]

A new Pull Request was created by @davidlange6 (David Lange) for CMSSW_7_1_X.

Reunify p sim hit map

It involves the following packages:

SimMuon/MCTruth
Validation/CSCRecHits
Validation/MuonCSCDigis

@civanch, @ojeda, @danduggan, @rovere, @cmsbuild, @nclopezo, @mdhildreth, @deguio, @Degano 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, @ktf you are the release manager for this.
You can merge this pull request by typing 'merge' in the first line of your comment.

[cmsbuild]

+1
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-3368/931/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-3368/931/summary.html

[deguio]

+1

[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). @nclopezo, @ktf can you please take care of it?