Add custom user settings UI.

- Adds UI in the keyboard help menu for setting custom GUI settings remembered
through localStorage.
- Adds option for force container support regardless of provider.
- Adds option to set the environmentName regardless of the deployment.
- Adds option to disable the EU cookie notice.
Merge pull request #601 from mitechie/add-config

Add custom user settings UI.

- Adds UI in the keyboard help menu for setting custom GUI settings remembered
through localStorage.
- Adds option for force container support regardless of provider.
- Adds option to set the environmentName regardless of the deployment.
- Adds option to disable the EU cookie notice.