Get rid of general outflow BC type
Evolved from #878 (closed).
Move to old staggered only, kick out of the general BC types. For porous medium flow, it doesn't have any effect. Evaluate how to treat the sequential stuff.
Evolved from #878 (closed).
Move to old staggered only, kick out of the general BC types. For porous medium flow, it doesn't have any effect. Evaluate how to treat the sequential stuff.