Fix warnings in substrate (#1523)

* Fix warnings in substrate

* More warnings removed and wasm updated

* Fixes error on stable and grumbles

* Update wasm files

* Add links to the github issue for replacing `error-chain`

substrate/core/client/src/error.rs

@@ -16,6 +16,9 @@
 
 //! Substrate client possible errors.
 
+// Silence: `use of deprecated item 'std::error::Error::cause': replaced by Error::source, which can support downcasting`
+// https://github.com/paritytech/substrate/issues/1547
+#![allow(deprecated)]
 #![allow(missing_docs)]
 
 use std;