Multiple pickup configurations

[johlindr]

Would need to be able to display different pickup dates/intervals each day based on products.

We would really need a hook to be able to dynamically filter/control the available pickup times based on for example cart content or other criteria.

example, if cart contains productX available pickup times is only between 17 - 20.00 (while the plugin setting allows for example 10 - 22.00).

optimal would be if it would be possible to give start, endtime, days ahead, delay from order, interval dynamically via a hook on the checkout page.

[timnolte]

Partially related to #58 .

[timnolte]

Partially related to #57