Upgrade to substrate rc6 (#13)

* Upgrade to rc6

* Initial runtime port

* The rest of the owl

* add wasmtime features

* Copy node template manifest

* Copy dependencies order from node-template for easier updating

* Update contracts runtime rpc api, other errors

* Fix some contracts stuff

* Fix up builder runner

* Increment spec and impl versions

* Compiles. Works?

* Test with --release to reuse just completed compilation (from #5)