TODO

# Open Questions
1. Flesh out the rebase algorithm
  - Figure out which commits are shared between the two branches' histories
    - These are commits that are found from the divergent changes in each branch
2. Collapse chains of rewrites when they haven't been shared with an upstream
  - Do this on push? Ask first?
3. Figure out how to mark branches as stable.
   - When there are no upstream changes after excluding stable ones, just exec
     normal git.
   - Any time there are no commits in common, exec normal git.
4. Should --force be required if some upstream changes are not present in what is being pushed?
   - For the gerrit workflow, I'd say no since the missing changes aren't being removed in any way.
   - For the github workflow, the changes may go missing.
   - Make sure that merged changes are taken into account.

# Open Questions, things I could work on.
- Need a way to print the log for a change
- Need a way to diff commits from the same change
- Magic refs (e.g. refs/for/branch)

- Need a way to push/pull a change in case something was missed
  - Obsolete commits from a change can be pushed easily manually.
  - To fetch, you need to know the change id for a commit.
    - This can be done by running `git --ls-remote` and greping for the
      obsolete commit in the commit you have. Then, fetch all of the cheads
      from the same change id.
- Need a strategy to clean up old changes from the local repository (all the
  new heads)