Ethkey - extended keys (#4377)

* data structures initial

* hard derivation

* tabs, docs

* more docs

* soft private derivation

* public derivation

* finalize api, fix warnings

* use simple new()

* keypair api

* bump byteorder

* doc tweaks

* remove heavyness from tests

* added test vector infrastructure and examples

* initialization from seed to key pair

* add comment about panic

ethcore/Cargo.toml

@@ -24,7 +24,7 @@ semver = "0.5"
 bit-set = "0.4"
 time = "0.1"
 rand = "0.3"
-byteorder = "0.5"
+byteorder = "1.0"
 transient-hashmap = "0.1"
 linked-hash-map = "0.3.0"
 evmjit = { path = "../evmjit", optional = true }