DST sprucing output throws away MC information underlying event

Regarding the MC information, there is a distinction between productions to mDST and productions going to DST. For DST, we need to preserve /Event/MC/..., while for mDST only a subset of mcparticles can be saved (I believe they are stored in /Event/Spruce/HLT2/MC/...).

Currently, the /Event/MC/... location is thrown away (probably by accident) in the sprucing regardless of the output.