[PATCH] Pheonician levant has unreachable trees

[sanderd17]

Pheonician levant (or was it Phoenician) has a lot of unreachable trees on the map boundary.

It's easy to find them via the obstruction overlay.

This is because on square maps, there's a border of 3 tiles wide that's unpassable and allows the terrain to fade to black.

The following patch should fix it (apparently map size is expressed in tiles instead of meters?).

[sanderd17]

First patch messes up mountains on the edge, second patch doesn't