Run jet reco properly on miniAOD

[rappoccio]

This PR adds a bunch of changes necessary to run jet reco properly on miniAOD. There are a number of small changes related to using pat::Jets instead of reco::PFJets, and also generalized the input of PFCandidate to simply Candidate into the jet software to allow for pat::PackedCandidates.

Tests with the matrix worked for "-l limited" and "-l 1341.0". Also checked "scram b runtests" and that was also successful.

[cmsbuild]

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

Run jet reco properly on miniAOD

It involves the following packages:

CommonTools/RecoAlgos
DataFormats/PatCandidates
RecoJets/JetProducers

@nclopezo, @cvuosalo, @monttj, @cmsbuild, @slava77, @vadler can you please review it and eventually sign? Thanks.
@TaiSakuma, @ahinzmann, @yslai, @nhanvtran, @schoef, @mariadalfonso this is something you requested to watch as well.
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[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: 814307a
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7482/2262/summary.html

[slava77]

+1

for #7482 f5ef097

based on jenkins tests: there are no differences in reco outputs now;
I also looked at the PAT file outputs for 4.53 (Photon in 2012B): they seem to have ~the same size (patPackedCandidates_packedPFCandidates__PAT is the only branch with tiny changes, by 58 bytes or 0.5%; could be just a compression thing)

[monttj]

+1

[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 will be automatically merged.