Merged requested to merge feature/more-defaults-for-problem-interface-methods into next
- all dirichlet is the default for boundaryTypes
- source 0.0 is the source default
- neumann 0.0 is the neumann default
- 0 is the phase presence default
It was not feasible to make initial the default for dirichlet since dirichletAtPos can only call initialAtPos but we would like to call initial().
Fixes #356 (closed).