Use state machine externalities in validation runtime. (#214)

* test

* switch to branch

* Use modified.

* Use sp_externalities environmental primitives

* Change to latest no_std version, add missing host function boilerplate.

* remove comment (was used for debugging).

* fixes

* with_externalities factor

* Read merged change from overlay.

Author: cheme

Cargo.lock

@@ -21,6 +21,8 @@ sp-core = { git = "https://github.com/paritytech/substrate", default-features =
 sp-io = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 frame-executive = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 sp-trie = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
+sp-state-machine = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
+sp-externalities = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 
 # Polkadot dependencies
 parachain = { package = "polkadot-parachain", git = "https://github.com/paritytech/polkadot", default-features = false, features = [ "wasm-api" ] , branch = "master" }
@@ -48,6 +50,8 @@ std = [
 	"memory-db/std",
 	"hash-db/std",
 	"trie-db/std",
+	"sp-state-machine/std",
+	"sp-externalities/std",
 	"sp-trie/std",
 	"parachain/std",
 ]