add originalXWGTUP() to LHEEvent and LHEEventProduct 53X edition

[lgray]

Rebase of #2097 to CMSSW 53X

[cmsbuild]

A new Pull Request was created by @lgray (Lindsey Gray) for CMSSW_5_3_X.

add originalXWGTUP() to LHEEvent and LHEEventProduct 53X edition

It involves the following packages:

GeneratorInterface/LHEInterface
SimDataFormats/GeneratorProducts

@vciulli, @cmsbuild, @Degano, @bendavid, @nclopezo can you please review it and eventually sign? Thanks.
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@smuzaffar you are the release manager for this.
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[bendavid]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_5_3_X IBs unless changes or unless it breaks tests. @smuzaffar can you please take care of it?

[lgray]

@ktf this is missing only tests and ORP signing, can you please tell jenkins to take care of this one?
@davidlange6 +1 after tests, please?

[ktf]

@lgray, we currently do not have a jenkins rule for 53X, this is getting tested by hand.
@nclopezo can you try to see if you can copy and adapt the 71X test job to 53X? Thanks.

[davidlange6]

+1

[smuzaffar]

+tested