With EASY_BRIDGES off, bridge spans need to be next to a bridge tower
or a bridge head that is at least 20% efficient to remain standing.
When a bridge tower or head gets damaged below 20%, adjacent spans may
lose support. Bug: they don't fall when they're next to another
bridge head below 20%.
Has always been broken.
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
Stuff sitting on bridges isn't covered, yet. tests/fire has some. To
be moved here eventually.
The test exposes bugs. They're marked "BUG:" in the test input.
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
