Btag cond format

[HeinerTholen]

This pull request was originally here: #7633

@ferencek and Petra Van Mulders suggested to reopen it on 7_4_X since it does not affect the standard reco. The merge conflict from the last PR has been resolved.

EDIT: This PR was opened on 7_5_X, it wouldn't be needed anymore if this one is accepted: #7796

[cmsbuild]

A new Pull Request was created by @HeinAtCERN for CMSSW_7_4_X.

Btag cond format

It involves the following packages:

CondFormats/BTauObjects
RecoBTag/PerformanceDB

@nclopezo, @cvuosalo, @cerminar, @cmsbuild, @diguida, @slava77, @ggovi, @mmusich can you please review it and eventually sign? Thanks.
@ferencek, @acaudron, @pvmulder, @imarches 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.
You can merge this pull request by typing 'merge' in the first line of your comment.

[pvmulder]

This PR consists of added functionality for storing and reading b-tag scale factors from the database, necessary for the start of Run 2. As @HeinAtCERN pointed out, there is no impact on the reco sequence.

[cvuosalo]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_4_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

[ferencek]

@davidlange6, can you please merge this PR (it's been fully approved for more than a week and its 75X equivalent #7796 has already been merged)

[davidlange6]

+1