Declare several classes as non-storable

[Dr15Jones]

Several of the classes which are only used for interactive use
can not be stored since they will cause ROOT to crash if one requests
their StreamerInfo. This change just marks those classes as non persistent.
This change is needed for the threaded framework to know not to request
the construction of the StreamInfo for those classes.

[Dr15Jones]

@ktf One more change needed by THREADED_X but still a bug so should go into 7_0_X. Attempts to write such objects would crash ROOT so there should be no adverse affects from this change.

[cmsbuild]

A new Pull Request was created by @Dr15Jones (Chris Jones) for CMSSW_7_0_X.

Declare several classes as non-storable

It involves the following packages:

RecoParticleFlow/PFRootEvent

@nclopezo, @cmsbuild, @anton-a, @thspeer, @slava77, @Degano can you please review it and eventually sign? Thanks.
You can sign-off by replying to this message having '+1' in the first line of your reply.
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@ktf you are the release manager for this.

[Dr15Jones]

@ktf please override the signatures as long as the Jenkin's test pass. I need this and #1989 in before I make a pull request for _THREADED_X which loads all StreamerInfos else all RelVals for the _THREADED_X will crash.

[slava77]

ok to override from my side, assuming jenkins ok

[cmsbuild]

+1
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-1991/2030/summary.html

[cmsbuild]

+1
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-1991/2041/summary.html

[Dr15Jones]

@ktf please merge this.. Slava already said it is fine to override.