(svn r2156) -Fix: in revision 2104 someone forgot to add a very important check in
GetPrevVehicleInChain; this caused some nasty bugs in depots, like
wagons without engines complain about not being stopped, and stuff like
that. Hopefully this fixes those problems. With a big tnx to BJH for his
perfect demo!

#ifndef CALLBACK_TABLE_H
#define CALLBACK_TABLE_H

extern CommandCallback *_callback_table[];
extern const int _callback_table_count;

#endif