Concept for tracking changes

Create new commit (if possible)
If force is unset: Diff system's files against current state by copying them into the current state branch
Then, diff the package state against the state branch by dumping it
Else, or if no diff, continue
Copy normal config files into correct directories
Render and copy renderables
Retrieve explicitly installed packages and remove those that are not present in goal and install those that are not present in current state