Lazy reaping (#4895)

* Squash and rebase from gav-lazy-reaping

* Bump version

* Bump runtime again

* Docs.

* Remove old functions

* Update frame/balances/src/lib.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update frame/contracts/src/lib.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Warnings

* Bump runtime version

* Update frame/democracy/src/lib.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update frame/system/src/lib.rs

* Clean up OnReapAccount

* Use frame_support debug

* Bump spec

* Renames and fix

* Fix

* Fix rename

* Fix

* Increase time for test

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: Benjamin Kampmann <ben.kampmann@googlemail.com>

substrate/bin/node/testing/src/genesis.rs

@@ -69,15 +69,15 @@ pub fn config_endowed(
 		}),
 		pallet_session: Some(SessionConfig {
 			keys: vec![
-				(alice(), to_session_keys(
+				(dave(), alice(), to_session_keys(
 					&Ed25519Keyring::Alice,
 					&Sr25519Keyring::Alice,
 				)),
-				(bob(), to_session_keys(
+				(eve(), bob(), to_session_keys(
 					&Ed25519Keyring::Bob,
 					&Sr25519Keyring::Bob,
 				)),
-				(charlie(), to_session_keys(
+				(ferdie(), charlie(), to_session_keys(
 					&Ed25519Keyring::Charlie,
 					&Sr25519Keyring::Charlie,
 				)),