(svn r3992) -Fix: Rewrote the code to determine whether a rail-tile can be terraformed.
Fixes a bug where you could terraform a tunnel (fixed by r3228, but reverted that one)
Fixes a bug introduced by r3228 which allowed steep rail tiles resulting in ... unwanted effects such as display artifacts.
That means the terraform feature should not work as intended; it also uses _valid_tileh_slopes to determine valid configurations instead of hand-brewn stuff.
TODO: _terraform_err_tile and similar TileIndices should have INVALID_TILE as "unused", not 0. (0 is a valid tile).

/* $Id$ */

#ifndef NAMEGEN_H
#define NAMEGEN_H

typedef byte TownNameGenerator(char *buf, uint32 seed);

extern TownNameGenerator * const _town_name_generators[];

#endif /* NAMEGEN_H */