Steam store has major update to wallet code redemption

[Minosviel]

Steam store has been updated recently, and does not allow user to see information of the wallet code anymore (such as face value and formatted value). Wallet code will be redeemed straight away into the account.
As such, methods such as checkWalletCode() and redeemWalletCode() have stopped to work.

Now the only way to redeem the code is to POST via https://store.steampowered.com/account/ajaxredeemwalletcode/
with wallet_code and sessionid.

[DoctorMcKay]

Should be fixed in v2.2.1, but I don't have a wallet code on hand to test with, so please let me know if it doesn't work as expected.