Confusion between F and 2F

As pointed out by David:

Meanwhile, I noticed something in the core that made me pause: run_computefstatistic_single_point() returns 2F. MCMCTransientSearch.logl() calls this "FS" and does "return FS + self.likelihoodcoef" where from L~exp(F) I think it should >be F not 2F...? (Same for the base MCMC class, it just seems to have another wrapper function inbetween.)

I guess the sampler only ever needs relative likelihoods, anyway, so it doesn't make a difference...?

This needs to be cleaned up