Deprecate account management (#10213)

* Extract accounts from ethcore.

* Fix ethcore.

* Get rid of AccountProvider in test_helpers

* Fix rest of the code.

* Re-use EngineSigner, fix tests.

* Simplify EngineSigner to always have an Address.

* Fix RPC tests.

* Add deprecation notice to RPCs.

* Feature to disable accounts.

* extract accounts in RPC

* Run with accounts in tests.

* Fix RPC compilation and tests.

* Fix compilation of the binary.

* Fix compilation of the binary.

* Fix compilation with accounts enabled.

* Fix tests.

* Update submodule.

* Remove android.

* Use derive for Default

* Don't build secretstore by default.

* Add link to issue.

* Refresh Cargo.lock.

* Fix miner tests.

* Update rpc/Cargo.toml

Co-Authored-By: tomusdrw <tomusdrw@users.noreply.github.com>

* Fix private tests.

accounts/src/error.rs

@@ -0,0 +1,56 @@
+// Copyright 2015-2018 Parity Technologies (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use std::fmt;
+
+use ethstore::{Error as SSError};
+use hardware_wallet::{Error as HardwareError};
+
+/// Signing error
+#[derive(Debug)]
+pub enum SignError {
+	/// Account is not unlocked
+	NotUnlocked,
+	/// Account does not exist.
+	NotFound,
+	/// Low-level hardware device error.
+	Hardware(HardwareError),
+	/// Low-level error from store
+	SStore(SSError),
+}
+
+impl fmt::Display for SignError {
+	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+		match *self {
+			SignError::NotUnlocked => write!(f, "Account is locked"),
+			SignError::NotFound => write!(f, "Account does not exist"),
+			SignError::Hardware(ref e) => write!(f, "{}", e),
+			SignError::SStore(ref e) => write!(f, "{}", e),
+		}
+	}
+}
+
+impl From<HardwareError> for SignError {
+	fn from(e: HardwareError) -> Self {
+		SignError::Hardware(e)
+	}
+}
+
+impl From<SSError> for SignError {
+	fn from(e: SSError) -> Self {
+		SignError::SStore(e)
+	}
+}