Modifying terrains

[Sarilho1]

I would like to see some changes in the way the terrains are modifying or the maps created, in order to see a more realistic game. There are some:
- When, for some reason (pollution or intentionally), the sea has a direct contact with a lake, the lake would become sea.
- Rivers sources would be in mountains or hills in, approximately, 75% of all rivers generated. 15% in rainforests and 10% for other cases. (This percentages are just to illustrate my idea).
- When a world suffers a global warming, coastal cities, instead of becoming islands, should be destroyed or, at least, settlers would be automatically produced (if the city is size 8, 3 or 4 would be produced). These settlers would escape to a safe place nearby (if there is any), wasting motion points or they would enter to a free naval units to avoid death (e.g: triremes, transports ships...). The settlers that can't escape, die.

[cazfi]

- When, for some reason (pollution or intentionally), the sea has a direct contact with a lake, the lake would become sea.

Flooding lakes with seawater has been implemented to 2.5 development version.