Summary:
- Move "arc branch"-specific code to the branch workflow.
- Instead of doing "git rev-parse", just do "git branch --verbose --abbrev=40".
- Use revision owners to identify ownership, not working copy identity. Particularly with the advent of "Commandeer", you might not own commits you made.
- Do a batch lookup for commits by hash (depends on D2859, but doesn't break without it).
- Use PhutilConsole for console stuff.
- Removed color from "arc list" for the moment.
- The "--by-status" flag has a slightly different output format now.
Test Plan: Ran "arc branch" in various circumstances, verified it identifies branches in immutable history repositories.
Reviewers: btrahan, vrana, jungejason, nh, slawekbiel
Reviewed By: slawekbiel
CC: aran
Maniphest Tasks: T693
Differential Revision: https://secure.phabricator.com/D2860