(svn r3058) The default AI may not build dual headed trains under certain circumstances.
Simplify this check by testing the rail vehicle info flags instead of passing a global variable around.
Note: This is not exactly the original behaviour, because the Lev4 was always allowed to be built, but i guess that was a glitch.

/* $Id$ */

#ifndef NAMEGEN_H
#define NAMEGEN_H

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

extern TownNameGenerator * const _town_name_generators[];

#endif /* NAMEGEN_H */