DAO hard-fork (#1483)

* 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.

ethcore/src/json_tests/state.rs

@@ -30,8 +30,9 @@ pub fn json_chain_test(json_data: &[u8], era: ChainEra) -> Vec<String> {
 	let mut failed = Vec::new();
 	let engine = match era {
 		ChainEra::Frontier => ethereum::new_mainnet_like().engine,
-		ChainEra::Homestead => ethereum::new_homestead_test().engine
-	};
+		ChainEra::Homestead => ethereum::new_homestead_test().engine,
+		ChainEra::DaoHardfork => ethereum::new_daohardfork_test().engine,
+};
 
 	for (name, test) in tests.into_iter() {
 		let mut fail = false;