* Make `on_message` take the message as `&mut Option<_>`
* Make `ConsensusGossip` implement `Specialization`
* Move `new_session` into `ConsensusGossip`
* Adds `construct_simple_protocol` macro for simplifying the creation of protocols
* implement grandpa client
* consensus gossip with arbitrary topics
* defer GRANDPA messages until referenced blocks imported
* set up communication for voter in a transparent way
* instantiate GRANDPA voter
* keep last round state on disk
* switch back to crates.io finality-grandpa
* update cargo.lock
* use new `collect_garbage` API
* update sync test framework and make public
* test that observers can observe
* fix warning
* use more idiomatic predicate for collecting garbage in gossip
* kill spaces
* fix date
* Remove `node-api` from `node-consensus` and `node-transaction-pool`
* Remove the `node-api` crate and its last usages
* Remove left over file
* Fixes compilation errors
* Switch to `As` trait
* Rename trait
* Whitespace
* Remove unneeded script
* Rename Substrate Demo -> Substrate
* Rename demo -> node
* Build wasm from last rename.
* Merge ed25519 into substrate-primitives
* Minor tweak
* Rename substrate -> core
* Move substrate-runtime-support to core/runtime/support
* Rename/move substrate-runtime-version
* Move codec up a level
* Rename substrate-codec -> parity-codec
* Move environmental up a level
* Move pwasm-* up to top, ready for removal
* Remove requirement of s-r-support from s-r-primitives
* Move core/runtime/primitives into core/runtime-primitives
* Remove s-r-support dep from s-r-version
* Remove dep of s-r-support from bft
* Remove dep of s-r-support from node/consensus
* Sever all other core deps from s-r-support
* Forgot the no_std directive
* Rename non-SRML modules to sr-* to avoid match clashes
* Move runtime/* to srml/*
* Rename substrate-runtime-* -> srml-*
* Move srml to top-level