Use libraries syntax sugar for revoking grants logic

contracts/token/BasicToken.sol

@@ -15,7 +15,7 @@ contract BasicToken is ERC20Basic {
   mapping(address => uint) balances;
 
   /*
-   * Fix for the ERC20 short address attack  
+   * Fix for the ERC20 short address attack
    */
   modifier onlyPayloadSize(uint size) {
      if(msg.data.length < size + 4) {
@@ -33,5 +33,5 @@ contract BasicToken is ERC20Basic {
   function balanceOf(address _owner) constant returns (uint balance) {
     return balances[_owner];
   }
-  
+
 }