Support checkbox "My billing information is the same as my delivery information." checked by default

Problem/Motivation

In the dev version of Ubercart the option "Use the same address for billing and delivery by default." is added to the checkout settings. When checked, one of the address panes should be checked by default and the delivery address should be equal to the billing address in this case.
Ubercart Addresses does not yet respect this setting.
The issue in Ubercart where this feature got implemented: #1502774: Checkbox "My billing information is the same as my delivery information." checked by default.

Proposed resolution

Ubercart Addresses implementation of the address checkout panes should be adjusted, so the setting has the same effect as when Ubercart Addresses is not enabled.

Remaining tasks

• Adjust address checkout panes code.

Original report by Neo13

Based on issue and patch in this thread drupal.org/node/1502774 could you please implement this into ubercart addresses?

Many Thanks!