Serialisable genesis config (#229)

* Genesis serialization

* Custom type for AuthorityId

* Merge w master

* Fixed a few minor issues

* Fixed unmerged file

* Renamed tag

* Deferred genesis loading

* Upated wasm runtime

* Minor issues

substrate/demo/runtime/src/lib.rs

@@ -97,7 +97,7 @@ pub type Timestamp = timestamp::Module<Concrete>;
 pub struct SessionKeyConversion;
 impl Convert<AccountId, SessionKey> for SessionKeyConversion {
 	fn convert(a: AccountId) -> SessionKey {
-		a.0
+		a.0.into()
 	}
 }