Aggregate all liquidity restrictions in a single place (#1921)

* Clean up session key rotation

* Fix build

* Bump version

* Introduce feature to balances.

* Move staking locking logic over to central point

* ^^^ rest

* First part of assimilation

* More assimilation

* More assimilation

* Fix most tests

* Fix build

* Move Balances to new locking system

* :q!

* Bump runtime version

* Build runtime

* Convenience function

* Test fix.

* Whitespace

* Improve type legibility.

* Fix comment.

* More tests.

* More tests.

* Bump version

* Caps

* Whitespace

* Whitespace

* Remove unneeded function.

substrate/srml/council/Cargo.toml

@@ -5,7 +5,7 @@ authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
 [dependencies]
-serde = { version = "1.0", default-features = false }
+serde = { version = "1.0", optional = true }
 safe-mix = { version = "1.0", default-features = false}
 parity-codec = { version = "3.1", default-features = false }
 parity-codec-derive = { version = "3.1", default-features = false }
@@ -29,6 +29,7 @@ std = [
 	"parity-codec-derive/std",
 	"substrate-primitives/std",
 	"rstd/std",
+	"serde",
 	"runtime_io/std",
 	"srml-support/std",
 	"primitives/std",