Moving carton_uv from ringslegacy to here.
Fixing the carton_uv to work in pyrings.
Several changes including the montecarlo function

Sorry about that, I didn't realize that there were more changed stuff
- cfg['montcarlo'] to cfg['montecarlo']
- cosmetic, fitt.carton_uv to carton_uv
- Including the funciton montecarlo for the Monte Carlo simulations.
Cosmetics on importing modules.
Some issues with the penalized version. Moving back

It don't looks like to be a serious problem, but it's not the
  priority now.
Minor version update, to reflect the montecarlo() inclusion.