HLTTau producers migrated to consume

The following modules are migrated to consumes:
RecoTauTag/HLTProducers
-> CaloTowerCreatorForTauHLT
-> L2TauJetsMerger
-> L2TauPixelIsoTagProducer
-> TauJetSelectorForHLTTrackSeeding

Tested with 'frozen 2013' HLT table at CMSSW_7_1_0_pre3