(svn r4181) CodeChange : Replaced [G/S]etMapExtraBits by [G/S]etTropicZone. Although it was an accessor, nor his usage nor the values were clear.
/* $Id */
KNOWN BUGS / PROBLEMS:
Normal and elrail depots look the same. Use 'X' (transparent buildings)
to distinguish between them
Missing curors / icons for construction (currently using the conventional ones)