Transaction Fee Multiplier (#2854)

* added fee calculations; need some type conversions

* cleaned up make_payment and other stuff

* rename vars to compile

* add WeightToFee type

* clean test files after new type added to balances

* fmting

* fix balance configs in tests

* more fixing mocks and tests

* more comprehensive block weight limit test

* fix compilation errors

* more srml/executive tests && started fixing node/executor tests

* new fee multiplier; still overflows :(

* perbill at the end attempt; needs to be changed

* clean fmting, rename some vars

* new PoC implementation.

* test weight_to_fee range and verify functionality

* 12 of 15 tests in node executor are passing

* 1 test failing; big_block imports are failing for wrong reasons

* Update srml/executive/src/lib.rs

Co-Authored-By: Kian Peymani <Kianenigma@users.noreply.github.com>

* Some cleanup.

* consolidate tests in runtime impls

* clean and condition executive for stateful fee range test

* remove comments to self

* Major cleanup.

* More cleanup.

* Fix lock files.

* Fix build.

* Update node-template/runtime/Cargo.toml

Co-Authored-By: Gavin Wood <github@gavwood.com>

* Update node/executor/src/lib.rs

Co-Authored-By: Gavin Wood <github@gavwood.com>

* Update node/executor/src/lib.rs

Co-Authored-By: Gavin Wood <github@gavwood.com>

* Update node/executor/src/lib.rs

Co-Authored-By: Gavin Wood <github@gavwood.com>

* Update node/executor/src/lib.rs

Co-Authored-By: Gavin Wood <github@gavwood.com>

* Update node/executor/src/lib.rs

Co-Authored-By: Gavin Wood <github@gavwood.com>

* Update node/executor/src/lib.rs

Co-Authored-By: Gavin Wood <github@gavwood.com>

* Per-block update.

* nit.

* Update docs.

* Fix contracts test.

* Stateful fee update.

* Update lock files.

* Update node/runtime/src/impls.rs

* Revamped again with fixed64.

* fix cargo file.

* nits.

* Some cleanup.

* Some nits.

* Fix build.

* Bump.

* Rename to WeightMultiplier

* Update node/executor/src/lib.rs

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* Add weight to election module mock.

* Fix build.

* finalize merge

* Update srml/system/src/lib.rs

* Bring back fees.

* Some nits.

* Code shifting for simplicity.

* Fix build + more tests.

* Update weights.rs

* Update core/sr-primitives/src/weights.rs

* Update lib.rs

* Fix test build

substrate/node-template/runtime/src/lib.rs

@@ -15,7 +15,7 @@ use rstd::prelude::*;
 #[cfg(feature = "std")]
 use primitives::bytes;
 use primitives::{ed25519, sr25519, OpaqueMetadata};
-use runtime_primitives::{
+use sr_primitives::{
 	ApplyResult, transaction_validity::TransactionValidity, generic, create_runtime_str,
 	traits::{self, NumberFor, BlakeTwo256, Block as BlockT, StaticLookup, Verify}
 };
@@ -29,10 +29,10 @@ use version::NativeVersion;
 
 // A few exports that help ease life for downstream crates.
 #[cfg(any(feature = "std", test))]
-pub use runtime_primitives::BuildStorage;
+pub use sr_primitives::BuildStorage;
 pub use timestamp::Call as TimestampCall;
 pub use balances::Call as BalancesCall;
-pub use runtime_primitives::{Permill, Perbill};
+pub use sr_primitives::{Permill, Perbill};
 pub use support::{StorageValue, construct_runtime, parameter_types};
 
 /// Alias to the signature scheme used for Aura authority signatures.
@@ -56,6 +56,9 @@ pub type BlockNumber = u64;
 /// Index of an account's extrinsic in the chain.
 pub type Nonce = u64;
 
+/// Balance type for the node.
+pub type Balance = u128;
+
 /// Used for the module template in `./template.rs`
 mod template;
 
@@ -131,6 +134,8 @@ impl system::Trait for Runtime {
 	type Header = generic::Header<BlockNumber, BlakeTwo256>;
 	/// The ubiquitous event type.
 	type Event = Event;
+	/// Update weight (to fee) multiplier per-block.
+	type WeightMultiplierUpdate = ();
 	/// The ubiquitous origin type.
 	type Origin = Origin;
 	/// Maximum number of block number to block hash mappings to keep (oldest pruned first).
@@ -174,7 +179,7 @@ parameter_types! {
 
 impl balances::Trait for Runtime {
 	/// The type for recording an account's balance.
-	type Balance = u128;
+	type Balance = Balance;
 	/// What to do if an account's free balance gets zeroed.
 	type OnFreeBalanceZero = ();
 	/// What to do if a new account is created.