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/frame/generic-asset/src/lib.rs

@@ -1124,7 +1124,7 @@ impl<T: Subtrait> frame_system::Trait for ElevatedTrait<T> {
 	type ModuleToIndex = ();
 	type AccountData = ();
 	type OnNewAccount = ();
-	type OnReapAccount = ();
+	type OnKilledAccount = ();
 }
 impl<T: Subtrait> Trait for ElevatedTrait<T> {
 	type Balance = T::Balance;

substrate/frame/generic-asset/src/mock.rs

@@ -64,7 +64,7 @@ impl frame_system::Trait for Test {
 	type ModuleToIndex = ();
 	type AccountData = ();
 	type OnNewAccount = ();
-	type OnReapAccount = ();
+	type OnKilledAccount = ();
 }
 
 impl Trait for Test {