Add Attachments Macro (and Tools->Attachments) plugin point to insert columns into file list

It would be great if Confluence could establish a plugin point to add arbitrary columns to the file lists used in the Attachments Macro and Tools->Attachments parts of the system. Some of our add-ons need to mark up the Attachments file lists with new columns, and we would love to have a standardized way to do this.

One possible implementation that would work for us would be along the following lines:

Create a new <web-item>, containing:

• an i18n column title to be inserted in the <th>
• a style class to be applied to the <th> and <td>
• a weight to position the column amongst other add-on links. For us, it would be sufficient to insert the plugin-supplied links all at the right hand side, immediately before any attachment actions...but if you wanted to go all-out and make all of the system attachment columns into their own web-items and permit a completely arbitrary rendering order, that would also work.
• a Velocity context containing just a reference to the attachment itself (and/or attachment version)

With the current implementation of the attachments macro and Tools->Attachments page, we would presumably need three different web-item sections:

1- the Tools->Attachments page,
2- the top-level Attachments Macro list (which contains just the file name and modified date), and
3- the Attachments Macro version list (containing the version name, creator and date)