Add the following:
* Container name, machine name, worker id.
* Container uptime, puma uptime, worker uptime.
* Number of requests processed by current worker.
* ExifTool version.
Also change /status page to show information in tables instead of lists.
Show the HTTP request headers and the client IP on the /status page.
This is for debugging request headers added by reverse proxies such as
Cloudflare and Nginx, and for making sure the client IP is correctly set
by the X-Forwarded-For header.
