Update Trac to 1.0.16

There are a bunch of useful bits in more recent TracTrac Trac is the place where contributors create issues for bugs or feature requests much like GitHub.https://core.trac.wordpress.org/. 1.0 releases that we could use.

Also, the TracXMLRPC pluginPlugin A plugin is a piece of software containing a group of functions that can be added to a WordPress website. They can extend functionality or add new features to your WordPress websites. WordPress plugins are written in the PHP programming language and integrate seamlessly with WordPress. These can be free in the WordPress.org Plugin Directory https://wordpress.org/plugins/ or can be cost-based plugin from a third-party had some compatibility issues with Trac 1.0, they were fixed in version 1.1.3, but there were also a handful of bug fixes in later versions, so upgrading that to 1.1.6 would be nice.