AF-30 Clustering implementation

[sparshev]

This change should add a proper clustering support with all the great functionality we had and even more with resistance to brain-split.

The change is BREAKING because removes the node description: not actually needed since all the decisions are made on the node itself.

TODO: Add more tests and proper documentation of each aspect of the cluster.

Related Issue

30

Motivation and Context

Without a p2p cluster - what a life?

How Has This Been Tested?

Automatically

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have signed the Adobe Open Source CLA.
• [x] My code follows the code style of this project.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.