git-codereview: begin to handle multiple-change branches

Gerrit supports multiple-change branches, and we'd like to make
git-codereview useful for people using this mode of work.
This CL is the first step.

- remove error message on detecting a multiple-change branch
- require 'git submit hash' in multiple-change branch
- make git submit, git sync cleanup safe for multiple-change branch
- adjust git pending output to show full information about multiple-change branch
- add pending -c to show only current branch, since output is getting long

We're not advertising or supporting this mode yet. For now the only
way to enter it is to run 'git commit' to create the second commit.
Perhaps eventually we will support something like 'git change -new'.

Change-Id: I8284a7c230503061d3e6d7cce0be7d8d05c9b2a3
Reviewed-on: https://go-review.googlesource.com/2110
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/git-codereview/review.go b/git-codereview/review.go
index 6d1f6ac..c8ed27a 100644
--- a/git-codereview/review.go
+++ b/git-codereview/review.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// TODO(rsc): Document multi-change branch behavior.
+
 // Command git-codereview provides a simple command-line user interface for
 // working with git repositories and the Gerrit code review system.
 // See "git-codereview help" for details.