Include B/Bbar dependence of the shower weight in the on-the-fly variations
Note that the difference is (fortunately) beyond the NLO accuracy of the method. However, it should be implemented for completeness, and it even appears to make a sizable difference in some cases.
This variation is missing in
rel-2-2-5 and on
rel-2-2-5 the B/Bbar factor can be enabled/disabled using the
CSS_USE_BBW setting. This setting is only read but never used on
master, so this should also be cleaned up with the new implementation.