Failsafe system dictionary for clustering.

• dictionary is managed as JSON.
• dictionary operations are idempotent, GetCAS(), GET(), SET(), DELETE() are REST compatible HEAD, GET, PUT and DELETE methods.
• JSON fields to GET(), SET() and DELETE() are specified as jsonpointer.
• system dictionary is meant to hold configuration and context information for the cluster.
• fault tolerance is achieved using raft protocol using go-raft implementations.
• can be used as a library and dictionary access APIs are natively available on the Server object.
• can be mounted on HTTP and accessed by remote client.
• can be muxed with web framework or HTTP applications using HTTPMuxer interface.