Transition calculates.

Proper break points are not done yet, and I'm far from having the optimiser done.
Calculating break points for the PSMC module
Added specification for number of intervals per epoch.
Use the intervals from Li & Durbin 2011
We need to scale time in number of mutations!
Optimiziation wrapper for PSMC module
Script for PSMC-like estimation
Merge branch 'feature/psmc_like_variation_in_coalescence_rate' into develop