Initial mechanics for 80:20 fee split (#2912)

* Initial mechanics for 80:20 fee split

Also:
- Introduce extra functions for Imbalance manipulation;
- Store treasury pot in an account, letting total issuance account for
  it.

* Fix some tests

* Fix some tests

* Minor cleanups

* Update parity-codec version (#2855)

* Update parity-codec version

* Update grandpa, rhododendron and trie-bench

* Use primitive-types from crates.io

* Bump impl version

* Fix trie-bench version

* Fix lock files

* Fix versions

* Update codec to 4.1

* merge fix

* Revert merge

* More reversions

* Remove accidental code

* Update locks

* Bump runtime

* Update locks

* Tweaks and label TODO

* Update srml/treasury/src/lib.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Update issue number

* Update core/sr-primitives/src/traits.rs

Co-Authored-By: Robert Habermeier <rphmeier@gmail.com>

* Fix wasm build

* Fix subkey build

substrate/node/runtime/Cargo.toml

@@ -16,6 +16,7 @@ offchain-primitives = { package = "substrate-offchain-primitives", path = "../..
 version = { package = "sr-version", path = "../../core/sr-version", default-features = false }
 support = { package = "srml-support", path = "../../srml/support", default-features = false }
 aura = { package = "srml-aura", path = "../../srml/aura", default-features = false }
+authorship = { package = "srml-authorship", path = "../../srml/authorship", default-features = false }
 balances = { package = "srml-balances", path = "../../srml/balances", default-features = false }
 contracts = { package = "srml-contracts", path = "../../srml/contracts", default-features = false }
 council = { package = "srml-council", path = "../../srml/council", default-features = false }
@@ -48,6 +49,7 @@ std = [
 	"runtime_primitives/std",
 	"support/std",
 	"aura/std",
+	"authorship/std",
 	"balances/std",
 	"contracts/std",
 	"council/std",