Asks user on whether or not to delete submissions/comments before doing so

As soon as I started using this on my last account, I realised that it was removing my comments with little to no warning. I merely wanted to migrate my subscriptions and delete my subscriptions, keeping my comments intact. Luckily I stopped the script before any of my comments were edited.

I'll warn you, though: The `y_or_n()` function is incredibly quick and dirty. Any better implementations are more than welcome!