fix(xLiquid): small fixes

Author: unknownunknown1

contracts/src/gateway/interfaces/IForeignGateway.sol

@@ -21,8 +21,6 @@ interface IForeignGateway is IArbitrator, IReceiverGateway {
 
     function withdrawFees(bytes32 _disputeHash) external;
 
-    // TODO: add withdrawal for ERC20?
-
     // For cross-chain Evidence standard
     function disputeHashToForeignID(bytes32 _disputeHash) external view returns (uint256);
 

contracts/src/gateway/xForeignGateway.sol

@@ -125,10 +125,10 @@ contract xForeignGateway is IForeignGateway {
     // ************************************* //
 
     function createDispute(
-        uint256 _choices,
-        bytes calldata _extraData
+        uint256 /*_choices*/,
+        bytes calldata /*_extraData*/
     ) external payable override returns (uint256 disputeID) {
-        // TODO
+        revert("Fees should be paid in WETH");
     }
 
     function createDisputeERC20(
@@ -195,7 +195,6 @@ contract xForeignGateway is IForeignGateway {
         arbitrable.rule(dispute.id, _ruling);
     }
 
-    // TODO: separate regular withdrawal from ERC20
     function withdrawFees(bytes32 _disputeHash) external override {
         DisputeData storage dispute = disputeHashtoDisputeData[_disputeHash];
         require(dispute.id != 0, "Dispute does not exist");

contracts/src/kleros-v1/kleros-liquid-xdai/WrappedPinakion.sol

@@ -3,7 +3,7 @@
 pragma solidity ^0.8;
 
 import "@openzeppelin/contracts/proxy/utils/Initializable.sol";
-import "../../libraries/SafeMath.sol";
+import "@openzeppelin/contracts/utils/math/SafeMath.sol";
 import "../interfaces/ITokenController.sol";
 import "./interfaces/ITokenBridge.sol";
 import "./interfaces/IERC677.sol";

contracts/src/kleros-v1/kleros-liquid-xdai/xKlerosLiquidToV2.sol

@@ -829,7 +829,6 @@ contract xKlerosLiquidToV2 is Initializable, ITokenController, IArbitrator {
     ) public payable override returns (uint256 disputeID) {
         require(msg.value == 0, "Fees should be paid in WETH");
         uint256 fee = foreignGateway.arbitrationCost(_extraData);
-        // TODO: give possibility to overpay. Use createDisputeERC20 function?
         require(weth.transferFrom(msg.sender, address(this), fee), "Not enough WETH for arbitration");
 
         (uint96 subcourtID, uint256 minJurors) = extraDataToSubcourtIDAndMinJurors(_extraData);
@@ -842,7 +841,7 @@ contract xKlerosLiquidToV2 is Initializable, ITokenController, IArbitrator {
         dispute.lastPeriodChange = block.timestamp;
         // As many votes that can be afforded by the provided funds.
 
-        uint256 nbVotes = msg.value / courts[dispute.subcourtID].feeForJuror;
+        uint256 nbVotes = fee / courts[dispute.subcourtID].feeForJuror;
 
         uint256 newLastRoundID = disputeNbRounds[disputeID];
         disputeNbVotesInRound[disputeID][newLastRoundID] = nbVotes;
@@ -853,7 +852,7 @@ contract xKlerosLiquidToV2 is Initializable, ITokenController, IArbitrator {
         dispute.tokensAtStakePerJuror.push(
             (courts[dispute.subcourtID].minStake * courts[dispute.subcourtID].alpha) / ALPHA_DIVISOR
         );
-        dispute.totalFeesForJurors.push(msg.value);
+        dispute.totalFeesForJurors.push(fee);
         dispute.votesInEachRound.push(0);
         dispute.repartitionsInEachRound.push(0);
         dispute.penaltiesInEachRound.push(0);