file_name - get the file name of an object

string file_name( object ob );

file_name() returns the name of the file from which 'ob' was loaded.
If the object is a cloned object, then file_name() will not be an
actual file on disk, but will be the name of the file from which the
object was originally cloned, appended with an octothorpe (#) and the
object instance number.  Object instance numbers start at 0 when the
game is booted, and increase by one for each object cloned, hence the
number is unique for each cloned object.  'ob' defaults to this_object()
if not specified.

 Tim Hollebeek  Beek@ZorkMUD, Lima Bean, IdeaExchange, and elsewhere
