[PATCH 1 of 3] merge: add state extras merge state data

[Durham Goode]

On 2/5/16 11:02 AM, Durham Goode wrote:
> # HG changeset patch
> # User Durham Goode <durham at fb.com>
> # Date 1454696128 28800
> #      Fri Feb 05 10:15:28 2016 -0800
> # Node ID 27579dd5295a4b41960c34e33287c2e9bdfc8113
> # Parent  01a5143cd25f285f8c745a92986cd7186bb32c90
> merge: add state extras merge state data
>
> In future commits we will want to store more data related to each file in the
> merge state. This patch adds an optional record for storing a dictionary of
> extras for each file.
>
This was meant to be a V2 series.  I've resent with the correct V2 flag.