Report diagnostic information

[tollmanz]

The recent update that shows missed events indicates that there may be an issue with cron in the installation. I would like to take this a bit further and try to actually diagnose the issue should one be present. I would need to research would exactly to check for, but this could be a very powerful debug feature.

[tollmanz]

I'm going to start listing things for diagnostic checks as I come across them.

• If using object cache, ensure that it is working. I recently ran into this in a dev environment where cron wasn't firing because the memcached server was not started.