StandardTokenExt: Making our token Recoverable

We inherit Recoverable in our token now, meaning that we can rescue tokens
accidentally sent to the token address.

Also MintableToken and ReleasableToken inheritance had to be changed to avoid
the diamond problem.

contracts/MintableToken.sol

@@ -5,7 +5,6 @@
  */
 
 import "zeppelin/contracts/token/ERC20.sol";
-import "zeppelin/contracts/ownership/Ownable.sol";
 import "./StandardTokenExt.sol";
 import "./SafeMathLib.sol";
 
@@ -18,7 +17,7 @@ pragma solidity ^0.4.6;
  * Only mint agents, contracts whitelisted by owner, can mint new tokens.
  *
  */
-contract MintableToken is StandardTokenExt, Ownable {
+contract MintableToken is StandardTokenExt {
 
   using SafeMathLib for uint;
 

contracts/ReleasableToken.sol

@@ -6,14 +6,13 @@
 
 pragma solidity ^0.4.8;
 
-import "zeppelin/contracts/ownership/Ownable.sol";
-import "zeppelin/contracts/token/ERC20.sol";
+import "./StandardTokenExt.sol";
 
 
 /**
  * Define interface for releasing the token transfer after a successful crowdsale.
  */
-contract ReleasableToken is ERC20, Ownable {
+contract ReleasableToken is StandardTokenExt {
 
   /* The finalizer contract that allows unlift the transfer limits on this token */
   address public releaseAgent;

contracts/StandardTokenExt.sol

@@ -7,6 +7,7 @@
 pragma solidity ^0.4.14;
 
 import "zeppelin/contracts/token/StandardToken.sol";
+import "./Recoverable.sol";
 
 
 /**
@@ -15,7 +16,7 @@ import "zeppelin/contracts/token/StandardToken.sol";
  * @notice Interface marker is used by crowdsale contracts to validate that addresses point a good token contract.
  *
  */
-contract StandardTokenExt is StandardToken {
+contract StandardTokenExt is Recoverable, StandardToken {
 
   /* Interface declaration */
   function isToken() public constant returns (bool weAre) {