Referral system v2

[tjcloa]

Pay referral fees in SOV

Initial task statement: #114
Should be implemented in a separate branch

Amendments

1. Take v1 affilites as the basis (without additional bonuses)
2. Change the rewards system:
   Affiliates only get reward in sov 5% of the trading fees (the trading fee amount is converted to sov and 5% accrued to affiliates to a new (to be created by Franklin) contract LockedSov:
   A mock contract can be used so far with this minimal interface:

/**
 * @notice Adds SOV to the locked balance of a user.
 * @param _userAddress The user whose locked balance has to be updated with _sovAmount.
 * @param _sovAmount The amount of SOV to be added to the locked balance.
 */
function depositSOVByAdmin(address _userAddress, uint256 _sovAmount) public {}

We already have rebates paid in sov.
For reference:

Sovryn-smart-contracts/contracts/mixins/FeesHelper.sol

Line 151 in 20e718e

(bool success, bytes memory data) =

            _priceFeeds.staticcall(
                abi.encodeWithSelector(
                    IPriceFeeds(_priceFeeds).queryReturn.selector,
                    feeToken,
                    protocolTokenAddress, // price rewards using SOV price rather than vesting token price
                    feeAmount.mul(feeRebatePercent).div(10**20)
                )
            );

For the details on the LockedSov contract the best to ask is @powerhousefrank