Backporting to beta (#3149)

* The front-end for each hard-fork, also EIP-160.

* Address EIP161 a/c

* Include EIP-161b

* EIP-161 part d.

* Fix test build.

* Fix one test, add another.

* Fix use of bloom & renaming.

* Fixed tests

* Initial groundwork for EIP-155

* Fix minor bug.

* Fix all tests finally.

* Rest of EIP-155.

* Add tests for EIP-155 algorithm.

Update transaction tests validation.

* Address grumbles.

* Remove unused code.

* Resolve IPC issues

* Fixed tests

* ipc backports

* Fixing random test failures (#2577)

* Fix SUICIDE gas mechanism and add consensus tests.

* Remove commented code.

* Set Frontier hardfork block number

* Transaction tests,

* Fixed tests

* Removed banning queue

rpc/src/v1/helpers/errors.rs

@@ -170,6 +170,7 @@ pub fn from_transaction_error(error: EthcoreError) -> Error {
 				format!("Transaction cost exceeds current gas limit. Limit: {}, got: {}. Try decreasing supplied gas.", limit, got)
 			},
 			InvalidGasLimit(_) => "Supplied gas is beyond limit.".into(),
+			e => format!("{}", e).into(),
 		};
 		Error {
 			code: ErrorCode::ServerError(codes::TRANSACTION_ERROR),