Changed payload proxy cache as required from Framework

[ggovi]

The caching policy of the PayloadProxy has been changed according to the requirements of the Framework. When a invalidateTransientCache() is requested in the DataProxy, a corresponding new function invalidateTransientCache() is called in the PayloadProxy. This call reset the Payload ( when available) and clears its Payload ID, while the current IOV is kept for further use.
The former function, invalidateCache(), which is resetting the entire IOV cache ( IOV+Payload), is currently not called by the Framework.

[cmsbuild]

A new Pull Request was created by @ggovi for CMSSW_7_3_X.

Changed payload proxy cache as required from Framework

It involves the following packages:

CondCore/CondDB
CondCore/ESSources

@apfeiffer1, @nclopezo, @cerminar, @cmsbuild, @diguida, @rcastello, @ggovi, @mmusich can you please review it and eventually sign? Thanks.
@ghellwig 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.
You can reject by replying to this message having '-1' in the first line of your reply.
@nclopezo you are the release manager for this.
You can merge this pull request by typing 'merge' in the first line of your comment.

[apfeiffer1]

+1

[Dr15Jones]

Thanks!

[cmsbuild]

+1
Tested at: 0509864
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-6388/872/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-6388/872/summary.html

[diguida]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_3_X IBs unless changes (tests are also fine). This pull request will be automatically merged.