Generalize the Consensus Infrastructure (#883)

* Split out Consensus
* Supply ImportQueue through network-service
  - simplify ImportQueue.import_blocks
  - remove Deadlock on import_block
  - Adding Verifier-Trait
  - Implement import_queue provisioning in service; allow cli to import
* Allow to actually customize import queue
* Consensus Gossip: Cache Message hash per Topic

substrate/core/consensus/rhd/Cargo.toml

@@ -0,0 +1,37 @@
+[package]
+name = "substrate-consensus-rhd"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+description = "Rhododendron Round-Based consensus-algorithm for substrate"
+
+[dependencies]
+futures = "0.1.17"
+parity-codec = { version = "1.1" }
+parity-codec-derive = { version = "2.0" }
+substrate-primitives = { path = "../../primitives" }
+srml-support = { path = "../../../srml/support" }
+sr-primitives = { path = "../../sr-primitives" }
+sr-version = { path = "../../sr-version" }
+sr-io = { path = "../../sr-io" }
+srml-consensus = { path = "../../../srml/consensus" }
+tokio = "0.1.7"
+parking_lot = "0.4"
+error-chain = "0.12"
+log = "0.3"
+rhododendron = { git = "https://github.com/paritytech/rhododendron.git", features = ["codec"] }
+serde = { version = "1.0", features = ["derive"] }
+
+[dev-dependencies]
+substrate-keyring = { path = "../../keyring" }
+substrate-executor = { path = "../../executor" }
+
+
+[features]
+default = ["std"]
+std = [
+	"serde/std",
+	"substrate-primitives/std",
+	"srml-support/std",
+	"sr-primitives/std",
+	"sr-version/std",
+]