[93x backport] Enable usage of TTreeCache in Fireworks

[osschar]

This is backport of #20702

[cmsbuild]

A new Pull Request was created by @osschar (Matevž Tadel) for CMSSW_9_3_X.

It involves the following packages:

DataFormats/FWLite
Fireworks/Core

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

cms-bot commands are listed here

[alja]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/23374/console Started: 2017/10/02 20:06

[cmsbuild]

+1
Tested at: 1cedb04
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20721/23374/summary.html

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:
9e8f9c9
You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20721/23374/git-log-recent-commits
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20721/23374/git-merge-result

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20721/23374/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 26
• DQMHistoTests: Total histograms compared: 2708283
• DQMHistoTests: Total failures: 230
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2707866
• DQMHistoTests: Total skipped: 187
• DQMHistoTests: Total Missing objects: 0
• Checked 107 log files, 9 edm output root files, 26 DQM output files

[Dr15Jones]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_9_3_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_9_4_X is complete. This pull request will now be reviewed by the release team before it's merged. @davidlange6, @slava77, @smuzaffar (and backports should be raised in the release meeting by the corresponding L2)

[davidlange6]

merge