support/codereview: remove mercurial support files

These files were used for the mercurual based codereview which is no
longer in place. Remove them and the containing folders.

Change-Id: Ie9b25d7141ed89ad4032bf26da31d75645fee5c4
Reviewed-on: https://go-review.googlesource.com/c/152897
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2 files changed