Change product markup to improve theming

The default product node output looks like this (+ indicates collapsed blocks, - indicates expanded blocks, like in Firebug):

- <div class="content">
  + <div class="product-image">
  + <div class="product-info product display">
  + <div class="product-info model">
    <p>
    this is the body of the product node
    <br/>
    "Filtered HTML" filter adds paragraph and line break tags
    </p>
    <p>no containing div for the body though ...</p>
  + <div class="product-info product sell">
  + <div class="add-to-cart">
  </div>

If the $node->body were wrapped in a <div></div>, CSS could be used to rearrange and style each of the blocks inside .content separately. For example, to move the image to the left and the text to the right, or simply apply a smaller font to the body text. As it stands, the body is not in a container so there's no CSS selector which will address all the body contents.

There's a short discussion of this issue at http://www.ubercart.org/forum/theming_and_design/11172/3_column_layout_n...

The attached patch defines a new theme function, theme_uc_product_body(), which is invoked from uc_product_view(). This has two positive effects: 1) Product bodies are now enclosed in a div, allowing CSS to affect the body contents, and 2) Providing a theme function means that users can override the function if necessary to modify the markup, without having to resort to writing a node-product.tpl.php.

After the patch, the above output looks like this:

- <div class="content">
  + <div class="product-image">
  + <div class="product-info product display">
  + <div class="product-info model">
  + <div class="product-body">
  + <div class="product-info product sell">
  + <div class="add-to-cart">
  </div>