Add Statemint (#452)

* Add Statemint

* Versioning.

* Fixes

* Fixes

* Fixes

* Fixes

* Fixes

* Benchmarking

* kick patch (paritytech/statemin#88)

* Westmint Chain Spec (paritytech/statemint#90)

* Tidy the common .toml

* Update weights

* add westmint sudo key comment

* Port consensus stuff

* fix typo

* fix typo ... again

* Recognise Westmint

Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>
Co-authored-by: Bastian Köcher <info@kchr.de>

Cargo.toml

@@ -8,6 +8,7 @@ members = [
 	"client/pov-recovery",
 	"client/service",
 	"pallets/aura-ext",
+	"pallets/collator-selection",
 	"pallets/dmp-queue",
 	"pallets/parachain-system",
 	"pallets/xcm",
@@ -20,6 +21,10 @@ members = [
 	"polkadot-parachains/pallets/ping",
 	"polkadot-parachains/rococo-runtime",
 	"polkadot-parachains/shell-runtime",
+	"polkadot-parachains/statemint-common",
+	"polkadot-parachains/statemint-runtime",
+	"polkadot-parachains/statemine-runtime",
+	"polkadot-parachains/westmint-runtime",
 	"test/runtime",
 	"test/runtime-upgrade",
 	"test/client",