The solver (class FullyImplicitBlackoilSolver<>) gained the ability
to do control mode switching/updating in commit 4a22c56 at which
point using WellsManager::conditionsMet() ceased to be useful. This
is a preparatory step towards adding support for RESV-type control
modes.
If we need this type of behaviour in the Simulator*, we can bring it
back (in modified form) at a later time.