Also includes API changes
- import everything from auxfun into init so instead of from phasefield.auxfun import ConcaveConvex write from phasefield import ConcaveConvex
- deprecate well argument from Model - set different well by changing well attribute on constructed model. Also move default well into phase model
- Make sure that fenics works again - a bit of a work around and at the moment the splitting of the bulk equations does not work (no product space used). All tutorials are adapted and seem to work as does the 'checkChange.py' script