* WIP
* Replace Rlp with UntrustedRlp in views, explicity unwrap with expect
First pass to get it to compile. Need to figure out whether to do this or to propogate Errors upstream, which would require many more changes to dependent code. If we do this way we are assuming that the views are always used in a context where the rlp is trusted to be valid e.g. when reading from our own DB. So need to fid out whether views are used with data received from an untrusted (e.g. extrernal peer).
* Remove original Rlp impl, rename UntrustedRlp -> Rlp
* Create rlp views with view! macro to record debug info
Views are assumed to be over valid rlp, so if there is a decoding error we record where the view was created in the first place and report it in the expect
* Use $crate in view! macro to avoid import, fix tests
* Expect valid rlp in decode functions for now
* Replace spaces with tabs in new file
* Add doc tests for creating views with macro
* Update rlp docs to reflect removing of UntrustedRlp
* Replace UntrustedRlp usages in private-tx merge
* Refactor updater to use ethabi-derive
* Grumble: do_call type alias
* Empty commit to trigger test re-run
* migration to ethabi-5.0
* migration to ethabi-5.0 in progress
* use ethabi_deriven to generate TransactAcl contract
* use ethabi_deriven to generate Registry contract
* hash-fetch uses ethabi_derive, removed retain cycle from updater, fixed#7720
* node-filter crate uses ethabi_derive to generate peer_set contract interface
* use LruCache in node-filter instead of HashMap
* validator_set engine uses ethabi_derive
* ethcore does not depend on native_contracts
* miner does no depend on native_contracts
* secret_store does not use native_contracts (in progress)
* removed native-contracts
* ethcore and updater does not depend on futures
* updated ethereum-types
* fixed all warnings caused by using new version of ethereum-types
* updated ethabi_derive && ethabi_contract to get rid of warnings
* removed another retain cycle in updater, fixed following minor version on update
* moved contracts out of native_contracts res
* updated ethabi_contract
* fixed failing test
* fixed failing test
* there is no need to create two contracts of the same kind any more
* simplify updater::ReleaseTrack conversion into u8 and add several tests for it
* applied review suggestions
* applied review suggestions
