git-review: expand pending output

for pending:
- show full commit message
- show information about being behind upstream
- show list of modified files
- for current branch, show staged, unstaged, untracked files
- warn about being ahead of upstream on master
- warn about being multiple commits ahead of upstream

- add same warnings to change
- add change -a (mostly unrelated, but prompted by this work)

Change-Id: Ie480ba5b66cc07faffca421ee6c9623d35204696
Reviewed-by: Rob Pike <>
Reviewed-by: Andrew Gerrand <>
7 files changed
tree: f23e58c4893cc23421c71bbd24a99792c8bcfcd0
  2. git-review/