Jupyterlab-server

- Add error message option [26](https://github.com/jupyterlab/jupyterlab_server/pull/26) ([blink1073](https://github.com/blink1073))
- Update settings handler to support JSON with comments. [25](https://github.com/jupyterlab/jupyterlab_server/pull/25) ([afshin](https://github.com/afshin))

- Add console error on error page [24](https://github.com/jupyterlab/jupyterlab_server/pull/24) ([blink1073](https://github.com/blink1073))

- Clean up static dir handling [23](https://github.com/jupyterlab/jupyterlab_server/pull/23) ([blink1073](https://github.com/blink1073))

- Do not cache themes [22](https://github.com/jupyterlab/jupyterlab_server/pull/22) ([blink1073](https://github.com/blink1073))

- Cleanup and handle no assets dir [20](https://github.com/jupyterlab/jupyterlab_server/pull/20) ([blink1073](https://github.com/blink1073))

- Fix handling of user settings dir [21](https://github.com/jupyterlab/jupyterlab_server/pull/21) ([blink1073](https://github.com/blink1073))