Merge branch 'development' into feature/testnet-faucets/order-dispenser

* development: (37 commits)
  Add dates to CHANGELOGs
  Change CHANGELOGs
  Add .editorconfig
  Fix a typo
  Temp
  Use forEach instead of map
  Add PR number
  Fix an exception when a signature collision happens
  Fix prettier
  Add regression tests
  Improve the comment and fix an exception
  Add missing comas
  Lerna-ignore tslint and tsconfig
  Update contract versions, fix tests
  Rename directories
  Rename previous contracts, fix imports, add nested file structure
  Move all contracts into a single directory
  Update import
  Fix import
  Get rid of suffixed contract versioning and replace it with a poor-mans package manager. Versions are stored locally, and are generated in a copy-on-write basis as required
  ...

1 files changed, 115 insertions, 0 deletions

diff --git a/packages/contracts/src/current/protocol/TokenTransferProxy/TokenTransferProxy.sol b/packages/contracts/src/current/protocol/TokenTransferProxy/TokenTransferProxy.sol
new file mode 100644
index 000000000..1ce949fa6
--- /dev/null
+++ b/packages/contracts/src/current/protocol/TokenTransferProxy/TokenTransferProxy.sol
@@ -0,0 +1,115 @@
+/*
+
+  Copyright 2017 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 ^0.4.11;
+
+import { Token_v1 as Token } from "../../../previous/Token/Token_v1.sol";
+import { Ownable_v1 as Ownable } from "../../../previous/Ownable/Ownable_v1.sol";
+
+/// @title TokenTransferProxy - Transfers tokens on behalf of contracts that have been approved via decentralized governance.
+/// @author Amir Bandeali - <amir@0xProject.com>, Will Warren - <will@0xProject.com>
+contract TokenTransferProxy is Ownable {
+
+    /// @dev Only authorized addresses can invoke functions with this modifier.
+    modifier onlyAuthorized {
+        require(authorized[msg.sender]);
+        _;
+    }
+
+    modifier targetAuthorized(address target) {
+        require(authorized[target]);
+        _;
+    }
+
+    modifier targetNotAuthorized(address target) {
+        require(!authorized[target]);
+        _;
+    }
+
+    mapping (address => bool) public authorized;
+    address[] public authorities;
+
+    event LogAuthorizedAddressAdded(address indexed target, address indexed caller);
+    event LogAuthorizedAddressRemoved(address indexed target, address indexed caller);
+
+    /*
+     * Public functions
+     */
+
+    /// @dev Authorizes an address.
+    /// @param target Address to authorize.
+    function addAuthorizedAddress(address target)
+        public
+        onlyOwner
+        targetNotAuthorized(target)
+    {
+        authorized[target] = true;
+        authorities.push(target);
+        LogAuthorizedAddressAdded(target, msg.sender);
+    }
+
+    /// @dev Removes authorizion of an address.
+    /// @param target Address to remove authorization from.
+    function removeAuthorizedAddress(address target)
+        public
+        onlyOwner
+        targetAuthorized(target)
+    {
+        delete authorized[target];
+        for (uint i = 0; i < authorities.length; i++) {
+            if (authorities[i] == target) {
+                authorities[i] = authorities[authorities.length - 1];
+                authorities.length -= 1;
+                break;
+            }
+        }
+        LogAuthorizedAddressRemoved(target, msg.sender);
+    }
+
+    /// @dev Calls into ERC20 Token contract, invoking transferFrom.
+    /// @param token Address of token to transfer.
+    /// @param from Address to transfer token from.
+    /// @param to Address to transfer token to.
+    /// @param value Amount of token to transfer.
+    /// @return Success of transfer.
+    function transferFrom(
+        address token,
+        address from,
+        address to,
+        uint value)
+        public
+        onlyAuthorized
+        returns (bool)
+    {
+        return Token(token).transferFrom(from, to, value);
+    }
+
+    /*
+     * Public constant functions
+     */
+
+    /// @dev Gets all authorized addresses.
+    /// @return Array of authorized addresses.
+    function getAuthorizedAddresses()
+        public
+        constant
+        returns (address[])
+    {
+        return authorities;
+    }
+}