Add greater functionality for the water level adjustment
For those that are not aware of this feature in the map editor because
it has no real use, here it is:
To elaborate, it would be great if the water level could actually fall
as well to maybe reveal more land underneath it or maybe even rise again
afterwards to have some sort of high-tide/low-tide effect. May have some
interesting effects on certain schemes.
Topic from T17 forums: http://forum.team17.com/showthread.php?t=40411