Modify DQMFileSaver to support new online use-cases.

Fixed wrong include.
Removed unused dependency from EventFiter package in DQMServices/StreamerIO/plugins BuidFile.
Use ak5 jets.
Make DQMFileSaver create also json files.
Use FilterUnit in tests.
Temporary fix: reset MEs if stored in PB format.
Temporary workaround: run step1 with PB on.
Provide json and data filenames with one single function.
save all the needed fields in the json file.
Remove unneeded pointers to MEs.
Include EvF services in DQMFileSaver.
Use the new location of the EvF services.
Remove not needed include in DQMFileSaver.cc
Use EvF services to get the path for files in Filter Unit.
Avoid the usage of string literals in the stream naming convention.
Use only one function for saving files in Filter Unit: the format is determined by enum passed as function parameter. This removes code duplication.
Fix definition field in the json file. CAVEAT: the slashes are escaped with backslash.
Fix source field in the json file.
Modify DQMStore to support new online use-cases.

Squashes onto 7_1_X:

new option for DQMStore to make all the MEs LS-based
add forceResetOnBeginLumi option to DQMStore
remove transitions which are not triggered anymore by the threaded framework
make DQMFileSaver create also json files.
reset lumi object instead of deleting it. needed for the online when saving per LS
simplify the logic of the indexes reset when running with enableMultiThread
correctly set flags default
bound forceResetOnBeginLumi and enableMultiThread together
percolate the enableMultiThread flag to the DQMFileSaver, MEtoEDMConverter and DQMRootOutputModule classes
force reset at the end of the LS for all the histograms when in FilterUnit mode and new tester now available
enabling the fuctionalities of the DQMFileSaver one by one
added offline use cases
remove useless ME booked in DQMFileSaver
Implements an input source for PB files.

Online DQM needs to load the Protobuf files produced by the FU.
This source also creates the required structure (run/lumi transitions)
to support the harvesting step.

Also this modifed the fastHadd to support primitive monitor elements.
However, unlike TH1 derived MEs, such elements are just copied around,
but are never merged.
Adding trigger selection for the DQMStreamerReader.
Various minor bug fixes to DQMStore and  DQMFileSaver.

Also add a few test cases to test the protobuf chain.
A bug fix in DQMFileSaver when saving PB/JSON files.
Optimizing the output of the DQMFileSaver when running on the FUs.
Merged refs/pull/4369/head from repository cms-sw
fix save method for HLXMonitor
test suite #1
upper bound only when running multithreading
clean up of the config file for DQMExample_Step1
Changes to json format used by DQMStreamerReader.
Fix a compilation error in the previous commit and make DQMProtobufReader to generate an empty lumi transitions instead of skipping them.
Merge pull request #4369 from dmitrijus/OnlineDQMMergeAttempt2

Major DQM update needed for the online