* state backend trait mirroring state_db API

* minimal state backend trait

make state module public

* fix json tests

* return errors on database corruption

* fix tests, json tests

* fix remainder of build

* add Backend bound on state

* Max gas limit and min gas price

* Tests

* Limit gas limit ceiling

* scope read

* consistent step

* Tweak some checks.

* Fixed build and added a difficulty test

make state module public

* Create new column family for local node info

* remove DBTransaction::new reliance on DB

* KeyValueDB trait

* InMemory KeyValueDB implementation

* journaldb generic over KVDB

* make most of `ethcore` generic over KVDB

* fix json tests compilation

* get all tests compiling

* implement local store (just for transactions)

* finish local store API, test

* put everything into place

* better test for skipping bad transactions

* fix warning

* update local store every 15 minutes

* remove superfluous `{}`s

* Default accounts setting - account provider

* RPC support for default accounts

* Updating JS code

* Rename whitelist to addresses

* Return condition info for pending transactions

* Fixed warnings

* initial in secret store

* generation

* test

* refactor of the derivation

* signing

* account provider

* tests for account provider

* rpc types

* rpc types converts

* rpc tests

* fix warnings

* some extra docs

* derivate -> derive

* secret() -> as_raw()

* secret() -> as_raw() in rpc

* fix merge bug

* align with new serde changes

* Signer - Tracking Request Provenance

* Basic UI

* Changing messages

* VecDeque::from

* Fix dapps tests

* Addressing UI grumbles

* Porting json

* Dapps

* Rpc & Ethstore

* New ethabi

* Last bunch of fixes

* Fixing last test

* Removing build script

* Adding ethcore-ipc-tests back

* Fixing grumbles

* Fixing blockchain tests (inference regression?)

* Ledger devices support

* structs for RPC types