Cleanup, delete OpenZeppelin contracts, use thier library instead

totalSupply -> totalSupply_ in JoyToken.sol according to:
OpenZeppelin/openzeppelin-contracts#666

Author: hbdgr

contracts/deposit/PlatformDeposit.sol

@@ -1,9 +1,10 @@
 pragma solidity ^0.4.11;
 
-import '../math/SafeMath.sol';
+import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';
+import 'openzeppelin-solidity/contracts/math/SafeMath.sol';
+
 import '../token/JoyToken.sol';
 import '../token/ERC223ReceivingContract.sol';
-import '../ownership/Ownable.sol';
 import '../game/JoyGameAbstract.sol';
 
 /**

contracts/game/JoyGameAbstract.sol

@@ -1,7 +1,6 @@
 pragma solidity ^0.4.11;
 
-import '../ownership/Ownable.sol';
-
+import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';
 
 contract JoyGameAbstract is Ownable {
 

contracts/game/JoyGameDemo.sol

@@ -1,8 +1,9 @@
 pragma solidity ^0.4.11;
 
+import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';
+import 'openzeppelin-solidity/contracts/math/SafeMath.sol';
+
 import '../deposit/PlatformDeposit.sol';
-import '../math/SafeMath.sol';
-import '../ownership/Ownable.sol';
 import './JoyGameAbstract.sol';
 
 

contracts/math/SafeMath.sol

@@ -1,7 +1,8 @@
 pragma solidity ^0.4.16;
 
+import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';
+
 import './Subscription.sol';
-import '../ownership/Ownable.sol';
 
 /**
  * Contract for purchasing subscriptions with ether on the owned platform

contracts/ownership/Ownable.sol

@@ -1,7 +1,8 @@
 pragma solidity ^0.4.16;
 
+import 'openzeppelin-solidity/contracts/ownership/Ownable.sol';
+
 import './Subscription.sol';
-import '../ownership/Ownable.sol';
 import '../token/ERC223ReceivingContract.sol';
 import '../token/JoyToken.sol';