Hello,

This is one more small iteration towards rerunning tau reconstruction from xAOD.
The tau AOD content has been slightly revised, we keep a new pi0 collection and drop another, but otherwise, this MR does not change the reconstruction output.
Further changes are expected, as the pi0 cell thinning is still work in progress.
Some modest memory improvement was made in the bookkeeping of already-processed pi0 cells, replacing a std::vector<CaloCell*> with a boost::dynamic_bitset<>.

Cheers,
Bertrand