[PATCH 3 of 4] py3: alias unicode to str on Python 3

[Yuya Nishihara]

On Fri, 07 Apr 2017 16:29:39 +0530, Pulkit Goyal wrote:
> # HG changeset patch
> # User Pulkit Goyal <7895pulkit at gmail.com>
> # Date 1491560884 -19800
> #      Fri Apr 07 15:58:04 2017 +0530
> # Node ID beedb62e62a78a2f45ef8bd0b72c51f14619ee7f
> # Parent  c08552f3a4ab883aac255bc7d8efb7637ba245d8
> py3: alias unicode to str on Python 3
> 
> diff -r c08552f3a4ab -r beedb62e62a7 mercurial/scmutil.py
> --- a/mercurial/scmutil.py	Fri Apr 07 13:46:35 2017 +0530
> +++ b/mercurial/scmutil.py	Fri Apr 07 15:58:04 2017 +0530
> @@ -36,6 +36,9 @@
>  
>  termsize = scmplatform.termsize
>  
> +if pycompat.ispy3:
> +    unicode = str

Let's add pycompat.unicode and/or importer magic. We'll need the unicode
type at several places.