Initial stop comment hinders output. 

With the following: 

```
> cat a.mli

(**/**)
val ha : string -> string
(**/**)


val bla : string -> string
(** [bla] is bla. *)
```

We get an odd `odoc-preamble` with `<p>/*</p>`  therein and the remaining output for the module is ommited. Adding an initial ocamldoc comment is a workaround. 


