[PATCH 3 of 3 V2] py3: add pycompat.unicode and add it to importer

[Yuya Nishihara]

On Sat, 08 Apr 2017 00:08:25 +0530, Pulkit Goyal wrote:
> # HG changeset patch
> # User Pulkit Goyal <7895pulkit at gmail.com>
> # Date 1491588351 -19800
> #      Fri Apr 07 23:35:51 2017 +0530
> # Node ID 7ce54c695ff7a5637b6798dec0fc6cf4f7b22098
> # Parent  1724a314de7c22936d33b09066e9f06197437391
> py3: add pycompat.unicode and add it to importer

Queued these, thanks.

> @@ -323,7 +324,7 @@
>      # ``replacetoken`` or any mechanism that changes semantics of module
>      # loading is changed. Otherwise cached bytecode may get loaded without
>      # the new transformation mechanisms applied.
> -    BYTECODEHEADER = b'HG\x00\x09'
> +    BYTECODEHEADER = b'HG\x00\x10'

Nit: I did s/10/0a/ in flight.