Unpin @0x/contracts-exchange dependency in /contracts/coordinator.

Split up EIP712 constants and functionality in `/contracts/exchange-libs` across 3, modular contracts.
Make coordinator inherit from the modular EIP712 contracts in `@0x\contracts-exchange`.

contracts/coordinator/contracts/src/libs/LibEIP712Domain.sol

@@ -19,24 +19,29 @@
 pragma solidity ^0.5.5;
 
 import "@0x/contracts-exchange-libs/contracts/src/LibEIP712.sol";
+import "@0x/contracts-exchange-libs/contracts/src/LibEIP712ExchangeDomainConstants.sol";
 import "./LibConstants.sol";
 
 
 // solhint-disable var-name-mixedcase
 contract LibEIP712Domain is
     LibConstants,
-    LibEIP712
+    LibEIP712,
+    LibEIP712ExchangeDomainConstants
 {
 
     // EIP712 Domain Name value for the Coordinator
     string constant internal EIP712_COORDINATOR_DOMAIN_NAME = "0x Protocol Coordinator";
 
     // EIP712 Domain Version value for the Coordinator
-    string constant internal EIP712_COORDINATOR_DOMAIN_VERSION = "1.0.0";
+    string constant internal EIP712_COORDINATOR_DOMAIN_VERSION = "2.0.0";
 
     // Hash of the EIP712 Domain Separator data for the Coordinator
     bytes32 public EIP712_COORDINATOR_DOMAIN_HASH;
 
+    // Hash of the EIP712 Domain Separator data for the Exchange
+    bytes32 public EIP712_EXCHANGE_DOMAIN_HASH;
+
     constructor ()
         public
     {
@@ -45,6 +50,11 @@ contract LibEIP712Domain is
             EIP712_COORDINATOR_DOMAIN_VERSION,
             address(this)
         );
+        EIP712_EXCHANGE_DOMAIN_HASH = hashEIP712Domain(
+            EIP712_EXCHANGE_DOMAIN_NAME,
+            EIP712_EXCHANGE_DOMAIN_VERSION,
+            address(this)
+        );
     }
 
     /// @dev Calculates EIP712 encoding for a hash struct in the EIP712 domain

contracts/exchange-libs/contracts/src/LibEIP712.sol

@@ -31,17 +31,6 @@ contract LibEIP712 {
         ")"
     ));
 
-    // EIP712 Exchange Domain Name value
-    string constant internal EIP712_EXCHANGE_DOMAIN_NAME = "0x Protocol";
-
-    // EIP712 Exchange Domain Version value
-    string constant internal EIP712_EXCHANGE_DOMAIN_VERSION = "3.0.0";
-
-    // Hash of the EIP712 Domain Separator data
-    // solhint-disable-next-line var-name-mixedcase
-    bytes32 public EIP712_EXCHANGE_DOMAIN_HASH;
-
-
     // Chain ID of the network this contract is deployed on.
     // solhint-disable-next-line var-name-mixedcase
     uint256 internal CHAIN_ID;
@@ -51,11 +40,6 @@ contract LibEIP712 {
         public
     {
         CHAIN_ID = chainId;
-        EIP712_EXCHANGE_DOMAIN_HASH = hashEIP712Domain(
-            EIP712_EXCHANGE_DOMAIN_NAME,
-            EIP712_EXCHANGE_DOMAIN_VERSION,
-            address(this)
-        );
     }
 
     /// @dev Calculates a EIP712 domain separator.

contracts/exchange-libs/contracts/src/LibEIP712ExchangeDomain.sol

@@ -0,0 +1,55 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.5;
+
+import "./LibEIP712.sol";
+import "./LibEIP712ExchangeDomainConstants.sol";
+
+
+contract LibEIP712ExchangeDomain is
+    LibEIP712,
+    LibEIP712ExchangeDomainConstants
+{
+    // Hash of the EIP712 Domain Separator data
+    // solhint-disable-next-line var-name-mixedcase
+    bytes32 internal EIP712_EXCHANGE_DOMAIN_HASH;
+
+    constructor ()
+        public
+    {
+        EIP712_EXCHANGE_DOMAIN_HASH = hashEIP712Domain(
+            EIP712_EXCHANGE_DOMAIN_NAME,
+            EIP712_EXCHANGE_DOMAIN_VERSION,
+            address(this)
+        );
+    }
+
+
+    /// @dev Calculates EIP712 encoding for a hash struct in the EIP712 domain
+    ///      of the Exchange contract.
+    /// @param hashStruct The EIP712 hash struct.
+    /// @return EIP712 hash applied to the Exchange EIP712 Domain.
+    function hashEIP712ExchangeMessage(bytes32 hashStruct)
+        internal
+        view
+        returns (bytes32 result)
+    {
+        return hashEIP712Message(EIP712_EXCHANGE_DOMAIN_HASH, hashStruct);
+    }
+}

contracts/exchange-libs/contracts/src/LibEIP712ExchangeDomainConstants.sol

@@ -0,0 +1,29 @@
+/*
+
+  Copyright 2018 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.5;
+
+
+contract LibEIP712ExchangeDomainConstants {
+
+    // EIP712 Exchange Domain Name value
+    string constant internal EIP712_EXCHANGE_DOMAIN_NAME = "0x Protocol";
+
+    // EIP712 Exchange Domain Version value
+    string constant internal EIP712_EXCHANGE_DOMAIN_VERSION = "3.0.0";
+}

contracts/exchange-libs/contracts/src/LibOrder.sol

@@ -18,11 +18,11 @@
 
 pragma solidity ^0.5.5;
 
-import "./LibEIP712.sol";
+import "./LibEIP712ExchangeDomain.sol";
 
 
 contract LibOrder is
-    LibEIP712
+    LibEIP712ExchangeDomain
 {
     // Hash for the EIP712 Order Schema
     bytes32 constant internal EIP712_ORDER_SCHEMA_HASH = keccak256(abi.encodePacked(
@@ -85,7 +85,7 @@ contract LibOrder is
         view
         returns (bytes32 orderHash)
     {
-        orderHash = hashEIP712Message(EIP712_EXCHANGE_DOMAIN_HASH, hashOrder(order));
+        orderHash = hashEIP712ExchangeMessage(hashOrder(order));
         return orderHash;
     }
 

contracts/exchange/contracts/src/MixinTransactions.sol

@@ -18,28 +18,18 @@
 
 pragma solidity ^0.5.5;
 
-import "@0x/contracts-exchange-libs/contracts/src/LibEIP712.sol";
+import "@0x/contracts-exchange-libs/contracts/src/LibEIP712ExchangeDomain.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibExchangeErrors.sol";
 import "./mixins/MSignatureValidator.sol";
 import "./mixins/MTransactions.sol";
 
 
 contract MixinTransactions is
-    LibEIP712,
+    LibEIP712ExchangeDomain,
     MSignatureValidator,
     MTransactions
 {
 
-    // EIP712 Domain Name value
-    string constant internal EIP712_DOMAIN_NAME = "0x Protocol";
-
-    // EIP712 Domain Version value
-    string constant internal EIP712_DOMAIN_VERSION = "3.0.0";
-
-    // Hash of the EIP712 Domain Separator data
-    // solhint-disable-next-line var-name-mixedcase
-    bytes32 public EIP712_DOMAIN_HASH;
-
     // Mapping of transaction hash => executed
     // This prevents transactions from being executed more than once.
     mapping (bytes32 => bool) public transactions;
@@ -47,16 +37,6 @@ contract MixinTransactions is
     // Address of current transaction signer
     address public currentContextAddress;
 
-    constructor ()
-        public
-    {
-        EIP712_DOMAIN_HASH = hashEIP712Domain(
-            EIP712_DOMAIN_NAME,
-            EIP712_DOMAIN_VERSION,
-            address(this)
-        );
-    }
-
     /// @dev Executes an exchange method call in the context of signer.
     /// @param salt Arbitrary number to ensure uniqueness of transaction hash.
     /// @param signerAddress Address of transaction signer.
@@ -77,7 +57,7 @@ contract MixinTransactions is
         );
 
         bytes32 transactionHash = hashEIP712Message(
-            EIP712_DOMAIN_HASH,
+            EIP712_EXCHANGE_DOMAIN_HASH,
             hashZeroExTransaction(
                 salt,
                 signerAddress,