[PATCH v4] rollback: add a config knob for entirely disabling the command

[Sean Farley]

Augie Fackler <raf at durin42.com> writes:

> # HG changeset patch
> # User Augie Fackler <augie at google.com>
> # Date 1462307605 14400
> #      Tue May 03 16:33:25 2016 -0400
> # Node ID 62ae5d974b76b3e61749fe89f11ae3bb176f487b
> # Parent  906a1c8a75fd8a18e43e8545eedcbe5222f84647
> rollback: add a config knob for entirely disabling the command
>
> This is of pretty high value for organizations that used to use p4 (as
> an example), since `p4 rollback` is what we call `hg backout`.

Looks good to me.