Remove Obsolete Header HideStdUniquePtrFromRoot.h

[wmtan]

Totally technical and trivial.
Back in the days of ROOT5 and CINT, gccxml did not understand C++11 constructs, such as std::unique_ptr. A header file, HideStdUniquePtrFromRoot.h, was written that defined our own
std::unique_ptr template that gccxml could understand.
In the ROOT6 world, this header is no longer needed, although for some reason an include of it still exists in one package,
This totally trivial and technical PR removes this obsolete unused header.

[cmsbuild]

A new Pull Request was created by @wmtan for CMSSW_8_1_X.

It involves the following packages:

DataFormats/TrackerRecHit2D
FWCore/Utilities

@smuzaffar, @Dr15Jones, @cvuosalo, @cmsbuild, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@makortel, @Martin-Grunewald, @gpetruc, @wddgit, @VinInn this is something you requested to watch as well.
@slava77, @Degano, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[wmtan]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/11936/console

[Dr15Jones]

+1

[cmsbuild]

-1
Tested at: 4977468
When I ran the RelVals I found an error in the following worklfows:
1000.0 step1

DAS Error

you can see the results of the tests here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-13745/11936/summary.html

[wmtan]

@cmsbuild @davidlange6 The DAS error in the relvals has noting to do with this PR.

[cvuosalo]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/11945/console

[cmsbuild]

+1
Tested at: 4977468
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-13745/11945/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-13745/11945/summary.html

[cvuosalo]

+1

For #13745 4977468

Deleting an obsolete header file. There should be no change in monitored quantities.

Jenkins tests against baseline CMSSW_8_1_X_2016-03-16-2300 show no significant differences, as expected.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_1_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @Degano, @smuzaffar