spkg: iter_buf

Iterate through buffer line by line and terminate just before eof.

Parameters:

	b	begining of the line
	e	one character after the end of the line (excluding )
	eof	end of the buffer (after the last valid character eof = b + length)
	n	next line start (set this to the buffer begining at start)
	ln	line (zero terminated g_strduped string, freed by user) (could be zero if you don't want to us it)

Returns:

0 if not a valid cleanup link line, 1 if valid

  gchar *b, *e, *ln, *n=buf, eof=buf+strlen(buf);
  while(iter_lines(&b, &e, &n, eof, &ln))
  {
    g_free(ln);
  }