Add support for custom deleter to edm::ReusableObjectHolder

[makortel]

PR description:

This PR adds support for custom deleter to the edm::ReusableObjectHolder<T>. The deleter type must be the same on all objects, and is a template parameter to the ReusableObjectHolder<T, Deleter>, defaulting to std::default_delete<T> (like in std::unique_ptr). For non-default deleters the object-making function must return std::unique_ptr<T, Deleter> (for default deleter a raw pointer T* is still allowed).

The deleter is allowed to have state, and the deleter object is passed around (between the returned std::shared_ptr and the internal tbb::concurrent_queue) along with the object T. The deleter object must be copyable.

PR validation:

Unit tests run, limited matrix runs.

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-28004/11908

• This PR adds an extra 20KB to repository

[cmsbuild]

A new Pull Request was created by @makortel (Matti Kortelainen) for master.

It involves the following packages:

FWCore/Utilities

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

cms-bot commands are listed here

[makortel]

@cmsbuild, please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-run-pr-tests/2533/console Started: 2019/09/16 17:37

[cmsbuild]

+1
Tested at: d70d7a5
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-b127b2/2533/summary.html

[cmsbuild]

Comparison job queued.

[Dr15Jones]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @davidlange6, @slava77, @smuzaffar, @fabiocos (and backports should be raised in the release meeting by the corresponding L2)

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-b127b2/2533/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 34
• DQMHistoTests: Total histograms compared: 2957336
• DQMHistoTests: Total failures: 1
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2956994
• DQMHistoTests: Total skipped: 341
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 33 files compared)
• Checked 145 log files, 15 edm output root files, 34 DQM output files

[fabiocos]

+1