Move the substate module into ethcore/executive (#10867)

* substate is not a part of account-state

* fn cleanup_mode is a part of executive.rs

* test_cleanup_mode

ethcore/src/tests/evm.rs

@@ -21,7 +21,7 @@ use hash::keccak;
 use vm::{EnvInfo, ActionParams, ActionValue, CallType, ParamsType};
 use evm::{Factory, VMType};
 use executive::Executive;
-use account_state::Substate;
+use substate::Substate;
 use test_helpers::get_temp_state_with_factory;
 use trace::{NoopVMTracer, NoopTracer};
 use types::transaction::SYSTEM_ADDRESS;