* cleanup parity/signer
* remove redundant import of signer crate from main.rs
* rpc and signer are no longer optional
* move importing extern crates to main.rs file
* Display information on journal database on startup.
* Minor restyling.
* Client handles the enode message to avoid repeats.
* Avoid unneeded copies *and* reduce code.
* Fix up typo.
* Splitting methods requiring signing into separate trait
* Single place where RPC apis are created.
* Separating eth_filter
* Separating eth_signing
* Stubs for Personal Signer methods
* Test for EthSigningQueueClient
* TransactionConfirmation API
* Exposing PersonalSigner API
* Defining ApiSets dependent on context
* Removing types
* Supporting sending notification to WS connected SystemUIs
* Sending a notification on every new messages
* Adding logs to signing queue
* Shutting down broadcaster
* Refactoring the signing queue
* Fixing wait loop in case of spurious wake-ups.
