propagate the enableMT flag from DQMStore to MEtoEDMConverter and DQMRootOutputModule and make the DQMRootSource a friend with DQMStore
remove useles initialization
Merge pull request #4745 from deguio/propagateEnableMT

DQMServices -- propagate the enableMT flag from DQMStore to MEtoEDMConverter and DQMRoo...