Adds parallelisation support using ipyparallel
Adds parallelisation support using ipyparallel

1) Fitting procudure now runs with parallelisation for *all* stages if
an ipcluser instance is detected

2) Moves logic of fitting method to a separate function to avoid
repeated code

3) Fixed summarise_posterior to work of either the name, or N and skew.

ga7g08/BayesBimodalTest