A new feature whose purpose is to allow the DataMixingModule to mix premixed pileup that is stored as raw data.  A new python configuration file is added to DataMixingModule to support this.
The C++ changes in this tagset are also needed for this feature, but are much more general than that.  What the C++ changes really do is to give the DataMixingModule the ability to run producers (or filters) on demand in the secondary event (the event read by the secondary input source).
The (regular) MixingModule could be easily have given the same capability with trivial changes to the C++ code in SimGeneral/MixingModule.  This is not done because it introduces an undesirable dependency on an unrelated feature (new TrackingParticle), which also touches SimGeneral/MixingModule.

--- Tagset history ---
2013-06-14 21:59:44 - Queued by wmtan.
Merged tagset-133281 from repository ktf
Adapt to the new multithreaded API.
Merge pull request #56 from ktf/fix-conflict-in-pr38

Tagset 133281 + bugfix for non trivial multithread issue.