minimal state backend trait

make state module public

ethcore/src/tests/helpers.rs

@@ -349,7 +349,7 @@ pub fn get_temp_state_db() -> GuardedTempResult<StateDB> {
 	}
 }
 
-pub fn get_temp_state() -> GuardedTempResult<State> {
+pub fn get_temp_state() -> GuardedTempResult<State<::state_db::StateDB>> {
 	let temp = RandomTempPath::new();
 	let journal_db = get_temp_state_db_in(temp.as_path());
 
@@ -365,7 +365,7 @@ pub fn get_temp_state_db_in(path: &Path) -> StateDB {
 	StateDB::new(journal_db, 5 * 1024 * 1024)
 }
 
-pub fn get_temp_state_in(path: &Path) -> State {
+pub fn get_temp_state_in(path: &Path) -> State<::state_db::StateDB> {
 	let journal_db = get_temp_state_db_in(path);
 	State::new(journal_db, U256::from(0), Default::default())
 }