Adds copyBoundaryConditionFromFunction() method to BlockFunction
The commit moves the copyBoundaryConditionFromFunction()
method up from the P1CahnHilliardFunction
to its base class. Then other children can also make use of it.
The commit moves the copyBoundaryConditionFromFunction()
method up from the P1CahnHilliardFunction
to its base class. Then other children can also make use of it.