Goodbye, Snapshots.  

For review and commentary, not for merging yet.  This code is functional, but still has some UI issues

This pull request gets rid of the concept of keeping track of the state of the cluster over time, and folds the rest of the  functinoality we want to keep from snapshots back into deployments.  Now, propose and commit operations do not save state, instead they are gates that indicate whether the user can edit data and whether the annealer can operate on noderoles.

Snapshots as keeping a historical record of configuration changes in the cluster may be readded in a different form later.