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/indices/src/lib.rs

@@ -198,4 +198,7 @@ impl<T: Trait> StaticLookup for Module<T> {
 	fn lookup(a: Self::Source) -> result::Result<Self::Target, &'static str> {
 		Self::lookup_address(a).ok_or("invalid account index")
 	}
+	fn unlookup(a: Self::Target) -> Self::Source {
+		address::Address::Id(a)
+	}
 }