Improve exception message for unscheduled circular dependences

--- Tagset history ---
2013-06-19 18:03:39 - Queued by wdd.
Adapt to a minor pending change in the framework, by freezing the product registry through a non-const pointer, rather than a const pointer.  The "setFrozen()" function is currently a const function, although it modifies the class.  For thread safety reasons, mutable members of the ProductRegistry will be made non-mutable, making setFrozen() a non-const function.  When that happens, this package will no longer compile.
This tag has no dependencies, because the non-const pointer is already supported, so it can be picked up before the framework change.

--- Tagset history ---
2013-06-26 01:13:29 - Queued by wmtan.
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.
Tagset 133281 is a new feature whose purpose is to allow the DataMixingModule to mix premixed pileup that is stored as raw data was queued as
The C++ changes in that 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 have easily been given the same capability in that tagset with trivial additions to the C++ code in SimGeneral/MixingModule, but that would have introduced an undesirable dependency on unrelated changes.  The unrelated changes have now been approved in 6_2_X, so this tagset is those minor additions to the mixing module.

--- Tagset history ---
2013-06-26 00:51:21 - Queued by wmtan.
prepare for the multithreaded framework by making the mutable data members of ProductRegistry nonmutable, and doing the same for some of the mutable data members of other registries. All member functions that modify these data members that were "const" functions were changed to non-const.

--- Tagset history ---
2013-06-26 20:24:28 - Queued by wmtan.
2013-06-26 20:30:35 - Commented by wmtan: All these tags, and those of all dependencies, were committed and tagged in CVS before the git migration.