reset-TTY-on-exit: copy more code from ncurses

The terminal sometimes still did not echo after an abort. Maybe this
will fix it...
black-oil model: chop the pressure update for a few iterations

for very large pressure updates, the delta values probably do not make
too much sense as the wells which are usually responsible for this
will change their regime, but this effect cannot be considered by the
Jacobian matrix, so limiting the damage seems to be a good idea...