Properly initialize embeddedTunePMuonBestTrack_ and embeddedTunePMuonBestTrack_, but also make the getter work on existing 7_0_6 files
Merged PatMuonBestTrackFix-fromCMSSW_7_0_6 from repository gpetruc
Merge pull request #4446 from nclopezo/pr-4359

pat::Muon best track embedding fix (7.0.X) Copied from #4359