How to track all changes made to your WP blog?

Hey guys and gals,

I recently had some changes made to my site on WordPress. Basically I had one guy fixing some code up so we could use SSL (https) and then another guy was fixing up the CDN services.

The funny thing is something got messed up and the site was in a loop. We found out why but both guys said they didn’t do it.

I have my sites hosted on Apache servers.

How can I check the logs and see who made the changes? Basically someone went into the general settings and changed the “Site Address (URL)”

Thanks for all the help in advance!