Add the possibility to choose between the Zemach or helicity formalisms
        for the angular distribution of the decay products.
Add the possibility to configure the resonances and amplitudes with or
        without the bugs of the BaBar implementation (Gounaris-Sakurai
        propagator and Blatt-Weisskopf coefficients).
Dummy commit to avoid all the caching mess to be around.

Reset to parent when working on this branch.