I don't know what to call this thing, but I'm doing the GitHub thing now.
This is just the beginning pieces of isolating installer-specific code that lives in blivet. This time around, the storage config is moved to blivet.osinstall out of blivet.blivet, and blivet.blivet.Blivet is significantly cleaned up as well. Everything's going to blivet.osinstall for the interim; eventually it's all going to be moved to anaconda when the timing is right, etc.
The commits tell a more robust story.