NAME
	GetProgramDir -- Returns a lock on the directory the program was loaded
			 from (V36)

   SYNOPSIS
	lock = GetProgramDir()
	D0

	BPTR GetProgramDir(void)

   FUNCTION
	Returns a shared lock on the directory the program was loaded from.
	This can be used for a program to find data files, etc, that are stored
	with the program, or to find the program file itself.  NULL returns are
	valid, and may occur, for example, when running a program from the
	resident list.  You should NOT unlock the lock.

   RESULT
	lock - A lock on the directory the current program was loaded from,
	       or NULL if loaded from resident list, etc.

   BUGS
	Should return a lock for things loaded via resident.  Perhaps should
	return currentdir if NULL.

   SEE ALSO
	SetProgramDir(), Open()