This release is almost a rewrite of the entire timer. The goal of the rewrite is to make it more conducive to plugins later, and really shouldn't have a lot of effect on the user experience of mist. You can check #12 to see exactly what was done in the state machine update. Other than that, some bugs have been fixed and unsplitting was implemented.
Also, there's now some more detailed documentation on split and configuration files on my website at https://periwinkle.sh/projects/mist/.