* Validating Host headers in RPC requests

* Fixing convention [ci skip]

* Remove extra indent.

[ci:skip]

fixed failing master

* Don't ping all nodes on start

* Fixed test

* Use tree index for DB

* Set uncles_hash, tx_root, receipts_root from verified block

* Use Filth instead of a bool

* Fix empty root check

* Flush block queue properly

* Expunge deref

* moving ipc deriving to trait

* refactoring of the client

* Asynchronous transactions (polling based for now).

- Alter eth_sendTransaction to be async, returning one of:
  - Transaction hash (signed and submitted).
  - Transaction promise ID (< 32 bytes).
  - Zero hash (will never be signed).
- Introduce new JSONRPC eth_checkTransaction.

The new API call takes a single argument - a promise ID. It returns
either:
- Transaction hash (signed and submitted).
- null (still pending, call again later),
- Zero hash (will never be signed).

* New RPC eth_postTransaction

- Restore previous semantics of sendTransaction.
- Introduce eth_postTransaction.
- Some refactoring.

* Fix minor lockup.

* Use TransientHashMap to prevent leak.

Sync stand-alone binary and feature-gated dependencies refactoring 

Re-enabling Parity UI

* BC locking; Recovery batch

* Missing state root recovery

* Test

* Multi-mode logging.

Better for miners (they get immediate notification of new block).
Better for general use (less superfluous information shown).

* Remove comment.

[ci:skip]

* Minor string change

[ci:skip]

* Minor message tweak.

* Minor tweaks and indentation fix.

* Util funtions to get OS-standard config path.

* Build fix.

* Optimize ethash verification

* disable WAL for puts

* Clear account cache after commit

* Commit only modified accounts

* Optimize existing block check

* Cache last hashes

* Delete values immediately from DB overlay

* Match remove behaviour; test

* Warning fixed

* Minor additions to allow resetting of code.

* Add test.

* Provisional DAO hard-fork proposal.

* Change to reflect latest HF spec.

* Include extradata restrictions and overrides.

* Introduce new tests.

* Update tests to new spec format.

* Allow JSON chain spec fields to be optional.

* Remove superfluous definitions. Fix overflow risk.

* Fix build.

* Add missing file.

* Remove old flag.

* Update to latest address set.

* Update tests and test spec to latest.

Change the mining default to release only on own transactions.

* fix network_start regression

* network io handler

* move registration to the network start

* die on DB from the future

* use error type to print messages, print db path