Weight annotation. (#3157)

* Make extrinsics extensible.

Also Remove old extrinsic types.

* Rest of mockup. Add tips.

* Fix some build issues

* Runtiem builds :)

* Substrate builds.

* Fix a doc test

* Compact encoding

* Extract out the era logic into an extension

* Weight Check signed extension. (#3115)

* Weight signed extension.

* Revert a bit + test for check era.

* Update Cargo.toml

* Update node/cli/src/factory_impl.rs

* Update node/executor/src/lib.rs

* Update node/executor/src/lib.rs

* Don't use len for weight - use data.

* Operational Transaction; second attempt (#3138)

* working poc added.

* some fixes.

* Update doc.

* Fix all tests + final logic.

* more refactoring.

* nits.

* System block limit in bytes.

* Silent the storage macro warnings.

* More logic more tests.

* Fix import.

* Refactor names.

* Fix build.

* Update srml/balances/src/lib.rs

* Final refactor.

* Bump transaction version

* Fix weight mult test.

* Fix more tests and improve doc.

* Bump.

* Make some tests work again.

* Fix subkey.

* Remove todos + bump.

* First draft of annotating weights.

* Refactor weight to u64.

* More refactoring and tests.

* New convert for weight to fee

* more tests.

* remove merge redundancy.

* Fix system test.

* Bring back subkey stuff.

* a few stress tests.

* fix some of the grumbles.

* Final nits.

* Update srml/system/src/lib.rs

Co-Authored-By: DemiMarie-parity <48690212+DemiMarie-parity@users.noreply.github.com>

* Scale weights by 1000.

* Bump.

* Fix decl_storage test.

substrate/core/test-runtime/src/lib.rs

@@ -34,8 +34,7 @@ use substrate_client::{
 	impl_runtime_apis,
 };
 use runtime_primitives::{
-	ApplyResult,
-	create_runtime_str,
+	ApplyResult, create_runtime_str, Perbill,
 	transaction_validity::{TransactionValidity, ValidTransaction},
 	traits::{
 		BlindCheckable, BlakeTwo256, Block as BlockT, Extrinsic as ExtrinsicT,
@@ -330,6 +329,7 @@ parameter_types! {
 	pub const MinimumPeriod: u64 = 5;
 	pub const MaximumBlockWeight: u32 = 4 * 1024 * 1024;
 	pub const MaximumBlockLength: u32 = 4 * 1024 * 1024;
+	pub const AvailableBlockRatio: Perbill = Perbill::from_percent(75);
 }
 
 impl srml_system::Trait for Runtime {
@@ -346,6 +346,7 @@ impl srml_system::Trait for Runtime {
 	type BlockHashCount = BlockHashCount;
 	type MaximumBlockWeight = MaximumBlockWeight;
 	type MaximumBlockLength = MaximumBlockLength;
+	type AvailableBlockRatio = AvailableBlockRatio;
 }
 
 impl srml_timestamp::Trait for Runtime {