Set up beta doubling.

I calculate betaSteps as before (on the master node only) and then broadcast betasteps and the starting value of beta to all the nodes.
Now each beta step is a “negative bin” I start the bin loop with i=-beta steps and at the end of every negative bin I double beta (on each replica separately, no communication required).
i=0 bin is the normal, betaMax equilibration step.
For each bin i<=0, I to isteps MC sweeps rather than mcsteps.