Beta Backports (#4012)

* Fix up the transaction JSON serialisation for RPC.

* Introduce to_hex() utility in bigint. Fix tests.

Conflicts:
	rpc/src/v1/tests/mocked/eth.rs
	rpc/src/v1/tests/mocked/signing.rs
	rpc/src/v1/types/block.rs
	rpc/src/v1/types/transaction.rs

* fix comment

* Fix build.

* Bump hyper

* Correct log index in transaction receipt (#3995)

* Moving logs to separate, testable function

* Adding test

* Fixing log index

* Adding transaction log index

* Fixing rpc tests

* Making interface of  a bit cleaner.

Conflicts:
	ethcore/src/client/client.rs
	ethcore/src/tests/client.rs
	ethcore/src/types/transaction.rs

* Encode networkid as a u64.

Conflicts:
	ethcore/src/types/transaction.rs

* Fixing compilation issues

* parse testnet chain as ropsten

* Removing unused import