Quick URL selection in the urlselection overlay

This is a quick and simple hack in order to make url selection a bit more intuitive and easy.
Instead of having to hit enter, if the amount of numbers you've entered shares the same amount of digits as the largest link number, it will automatically be opened.

The addition defaults to off, in order to turn it on you need to add "quick_url=true" to your config file.

Any comments are obviously appreciated.