convert ERC721Full, ERC721Enumerable, ERC721Metadata to initializers

contracts/mocks/ERC721FullMock.sol

 pragma solidity ^0.4.24;
 
+import "../Initializable.sol";
 import "../token/ERC721/ERC721Full.sol";
 import "../token/ERC721/ERC721Mintable.sol";
 import "../token/ERC721/ERC721Burnable.sol";
@@ -10,11 +11,12 @@ import "../token/ERC721/ERC721Burnable.sol";
  * This mock just provides a public mint and burn functions for testing purposes,
  * and a public setter for metadata URI
  */
-contract ERC721FullMock is ERC721Full, ERC721Mintable, ERC721Burnable {
+contract ERC721FullMock is Initializable, ERC721Full, ERC721Mintable, ERC721Burnable {
   constructor(string name, string symbol) public
-    ERC721Mintable()
-    ERC721Full(name, symbol)
-  {}
+  {
+    ERC721Full.initialize(name, symbol);
+    ERC721Mintable.initialize();
+  }
 
   function exists(uint256 tokenId) public view returns (bool) {
     return _exists(tokenId);

contracts/token/ERC721/ERC721Enumerable.sol

 pragma solidity ^0.4.24;
 
+import "../../Initializable.sol";
 import "./IERC721Enumerable.sol";
 import "./ERC721.sol";
 import "../../introspection/ERC165.sol";
 
 
-contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
+contract ERC721Enumerable is Initializable, ERC165, ERC721, IERC721Enumerable {
   // Mapping from owner to list of owned token IDs
   mapping(address => uint256[]) private _ownedTokens;
 
@@ -29,7 +30,10 @@ contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
   /**
    * @dev Constructor function
    */
-  constructor() public {
+  function initialize() public initializer {
+    ERC165.initialize();
+    ERC721.initialize();
+
     // register the supported interface to conform to ERC721 via ERC165
     _registerInterface(_InterfaceId_ERC721Enumerable);
   }

contracts/token/ERC721/ERC721Full.sol

 pragma solidity ^0.4.24;
 
+import "../../Initializable.sol";
 import "./ERC721.sol";
 import "./ERC721Enumerable.sol";
 import "./ERC721Metadata.sol";
@@ -11,9 +12,13 @@ import "./ERC721Metadata.sol";
  * Moreover, it includes approve all functionality using operator terminology
  * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
  */
-contract ERC721Full is ERC721, ERC721Enumerable, ERC721Metadata {
-  constructor(string name, string symbol) ERC721Metadata(name, symbol)
+contract ERC721Full is Initializable, ERC721, ERC721Enumerable, ERC721Metadata {
+  function initialize(string name, string symbol)
     public
+    initializer
   {
+    ERC721.initialize();
+    ERC721Enumerable.initialize();
+    ERC721Metadata.initialize(name, symbol);
   }
 }

contracts/token/ERC721/ERC721Metadata.sol

 pragma solidity ^0.4.24;
 
+import "../../Initializable.sol";
 import "./ERC721.sol";
 import "./IERC721Metadata.sol";
 import "../../introspection/ERC165.sol";
 
 
-contract ERC721Metadata is ERC165, ERC721, IERC721Metadata {
+contract ERC721Metadata is Initializable, ERC165, ERC721, IERC721Metadata {
   // Token name
   string internal _name;
 
@@ -26,7 +27,10 @@ contract ERC721Metadata is ERC165, ERC721, IERC721Metadata {
   /**
    * @dev Constructor function
    */
-  constructor(string name, string symbol) public {
+  function initialize(string name, string symbol) public initializer {
+    ERC165.initialize();
+    ERC721.initialize();
+
     _name = name;
     _symbol = symbol;