Fixed edible-biomass-growth-during-malfunction bug.

Total biomass growth is scaled back during malfunction but edible
biomass is not, negating the effect of a malfunction on food production.
In extreme cases, dry edible biomass could be driven larger that total
dry biomass, resulting in negative inedible dry biomass.

* Apply myProductionRate malfunction scaling to edible biomass and its
  low water correction.
Fixed production-rate-reduction-during-malfunction bug.

In several classes malfunctions are implemented by scaling back
production rate, the original intent apparently being to reduce it by
50%, 25%, and 10% for each severe, medium, and low malfunction.  As
implemented, the production rate was reduced to (not by) 50%, 25%, and
10% of its value for each severe, medium, and low malfunction,
resulting in low malfunctions being more severe than a severe ones.

* Applied production rate reduction correctly for severe, medium, and
  low malfunctions.