Coupon/Discount code mod

[jgweb2000]

There was a mod on 3.x.x that would allow you to specify coupon codes that would apply to paid subscriptions in the board. I could really benefit from this mod on 4.x.x.

I know this is the unpaid section, but I am willing to at least donate to have this mod update.

Thanks,
Jgweb2000