#129 `morale' dependency on happiness wrong

[Markus Armbruster]

From `info morale': The minimum values is based on
happiness: (morale_base) - happiness

This applies at the time of the morale command. If
your happiness goes down, units' doesn't change. Units
may have morale you couldn't set anymore. Stupid.

Morale should be clipped at the boundary dictated by
happiness when used, not necessarily when set.

If `morale' doesn't clip, players could say `morale 67
0' to make sure unit#67 has at all times the most
suicidal moral possible.

Of course, `land' must show the morale currently in effect.

Whoever chose high numeric morale values to mean low
morale ought to be flogged.