Make the original sell price available to $node object

Disclaimer: my understanding of Ubercart isn't good enough to tell if adding a price handler (http://drupal.org/node/619386) would solve this issue; feel free to mark as duplicate, in case.

I need to show the original sell_price along with the role-based one.
In uc_price_per_role_nodeapi the original price disappears. I think a quick workaround is to add something to the $node/product object that wouldn't break anything else and would be available for those interested.

Here's a patch. Simply adds $node->roleindependent_sell_price to the $node object at node_load. It applies to the dev version, though I only tested it on the release. A little documentation of the new value would also be a fair complement.