Re-introduce zero copy codec and add minimal polkadot client API which uses linked native runtime (#65)

* client-api type and move duty roster types to primitives

* tuple implementation for slicable

* mild cleanup of deserialization code

* stubs which handle encoding and decoding themselves

* fancier impl_stubs macro

* zero-copy slicable API

* minimal polkadot-client API

* fix WASM API generation

* move native environment stuff to substrate executor

* fix warnings and grumbles

- Everything polkadot becomes polkadot-.
- Wasm (substrate) executor tests split from Wasm (Polkadot) runtime and
built independently.

Bottom half minus tests builds.

Better debug tracing.

Gav Wood authored Jan 23, 2018 and Arkadiy Paronyan committed Jan 23, 2018

* Introduce basic skeleton for Polkador runtime.

* Clean up the runtime skeleton.

* Make initial runtime skeleton compile.

* Compile polkadot-runtime both for Wasm ad native, allowing for testing and direct usage.

* More fleshing out on runtime.

* Update native support.

* Fix warning.

* Update gitignore

* Update path.

* Fix path.

* Remove accidentally committed files.

* Add wasm binaries.

* Fix test.

* Native storage support API.

* Add environmental module

* Add native environment to make native source-code compatible with wasm.

Also tests.

* Finish up & polish environment stuff.

* Avoid using reentrancy issues.

* Add some docs and a test.

* Remove unneeded function.

* Documentation

* Tweak docs

* Remove TODOs.

* Balance transfers + util methods.

* Rejig tests and ensure authorities are addressed consistently.

* Add marshaller for xfer function

* Transaction dispatch test.

* Minor fix.

* Add test for ser/de transaction.

* Add ser/de for header.

* Add tests for header ser/de

* Introduce basic block decoding/execution framework.

* Introduce block decoding/execution framework (p2)

* Big refactor.

* Split out joiner.

* Hide away support modules.

* Fix up wasm runtime.

* use externalities for chain_id

* Clean up (Test)Externalities.

* Repot and introduce keccak-256 external.

* Signing with crypto.

* fix unsafety hole in environmental using function

* Introduce Ed25519 crypto.

* Repotting.

* Add ed25519_verify external.

* Introduce Ed25519 verify as an external.

* fix unsafety hole around unwinding

* Compile fixes.

* use new environmental API

* Tests for ed25519 verify.

* Polish

* Introduce UncheckedTransaction & test.

* Implement basic block and tx processing

* Introduce static hex and valid signature for block test.

* Repot session.

* comments.

* Refactor and timestamp test

* Remove fluff

* Remove fluff.

* Staking eras and tests.

* Implement sessions.

* Polish

* Test sessions.

* Introduce better hashing.

- Blake2 for secure hashing
- XX for fast hashing

* Fix tests.

* Introduce staking.

* Tests for simple staking system.

* Build fix for wasm.

* Fix tests.

* Repotting and docs.

* Docs and licence.

* Documentation.

* Remove superfluous code.

* Remove dummy key.

* Remove other superfluous file.

* Optimise with swap_remove