* Restore divide line below secondary nav bar, so that e.g. Issues is not in
the same space as the per repository Issues.
* Make secondary nav bar slightly more compact.
* Restore colored owner/repository name since this is information worth
highlighting to understand the context of what you're looking at.
* Slightly reduce contrast on divider lines.
* Fix inconsistent number pills styling on pull request page.
Use the same colors that `arc-green` imports from:
* Chroma from /web_src/less/themes/chroma/dark.less
* CodeMirror from /web_src/less/codemirror/dark.less
