RecoVertex/MultiVertexFit: clean -Wunused-function warnings

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
RecoTauTag/RecoTau: clean -Wunused-function warnings

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
add state to logwarning
Merge pull request #2556 from davidlt/clean-unused-function-RecoVertex-MultiVertexFit

GCC 4.9.0 -- RecoVertex/MultiVertexFit: clean -Wunused-function warnings
Merge pull request #2557 from davidlt/clean-unused-function-RecoTauTag-RecoTau

GCC 4.9.0 -- RecoTauTag/RecoTau: clean -Wunused-function warnings
Merge pull request #2572 from VinInn/verifyerr

Reco updates -- Add tracking state to Warning
Merge remote branch 'origin/CMSSW_7_1_X' into CMSSW_7_0_X