Make sp_core and sp_runtime dependencies optional, and bump to latest (#760)

* begin porting over traits; remove Config use of Hash

* port over the Header bits that we need

* sp_core_hashing where possible, move Verify to PairSigner, remove unused errors

* tidy up Config things and move related bits into one place

* fix codegen

* copy Era over

* move AccountId, Address, Signer to Signer trait and a pass over fixing examples

* impl MultiAddress, MultiSignature, AccountId32 and add back to Config (for decoding later)

* Copy over StorageKey, StorageData, StorageChangeSet

* subxt core compiling with no sp_core or sp_runtime

* Get examples compiling

* pass over fixing tests

* cargo fmt

* clippy tweaks and update polkadot.rs

* fix codegen docs

* port over special DigestItem encoding/decoding

* clippy and doc fixes

* cargo fmt and example fix

* more cargo fmt-ing...

* substrate-extra to substrate-compat

* cargo.toml comments

* simplify PairSigner trait bounds

* move RPC types to a separate file

* fix docs

* Add some tests for things and other PR feedback

* bump to latest sp deps

* avoid needing substrate-compat feature in a test

subxt/src/utils/mod.rs

@@ -4,7 +4,10 @@
 
 //! Miscellaneous utility helpers.
 
+pub mod account_id;
 pub mod bits;
+pub mod multi_address;
+pub mod multi_signature;
 
 use codec::{
     Decode,
@@ -13,6 +16,18 @@ use codec::{
 };
 use derivative::Derivative;
 
+pub use account_id::AccountId32;
+pub use multi_address::MultiAddress;
+pub use multi_signature::MultiSignature;
+
+// Used in codegen
+#[doc(hidden)]
+pub use primitive_types::{
+    H160,
+    H256,
+    H512,
+};
+
 /// Wraps an already encoded byte vector, prevents being encoded as a raw byte vector as part of
 /// the transaction payload
 #[derive(Clone, Debug, Eq, PartialEq)]