git-codereview: add [serverbranch] prefix for work on non-master server branches

For example this will add [dev.cc] to the work on the dev.cc (C to Go conversion) branch,
and it will add [release-branch.go1.4] to the upcoming 1.4.1 cherry-pick CLs.

Change-Id: I59fff85ced61453796b52c738a47ea1fc4a5bf36
Reviewed-on: https://go-review.googlesource.com/2782
Reviewed-by: Andrew Gerrand <adg@golang.org>
2 files changed
tree: d12fd7a4a42847954d694417eb23a4c987396fea
  1. git-codereview/
  2. .gitattributes
  3. README