Fish cause strange Dock placement behavior

[michael]

Fish allow the player to place a dock foundation, but do not allow the building to be constructed, so the units will continue trying to build the dock forever. Fish, via a vis dock placement, should have one of two behaviors:

-- The foundation can be placed and the fish are "destroyed."

or

-- Fish block foundation placement.

This is particularly a problem for the Carthaginian Naval Harbour, since its foundation footprint is so large.

[historic_bruno]

Ah, good find. I don't see why fish should block foundation placement, it's not like modern times where we have to spend millions and perform years of wildlife impact studies before building something :D

I'll look into expanding UnitAI, giving fish a special behavior such that they do nothing until they're told to move for a foundation, then they can destroy themselves. Then we could add more interesting fish behavior later if we so desired.

[ben]

(In [10153]) Fixes gaia animals without UnitAI (e.g. fish) blocking foundation construction, by destroying them. Fixes #936.