add new function for easier module integration

Hi,

I'm the maintainer of the Frequently Asked Questions module. Recently someone has requested support to display images attached to nodes (using image attach) on the generated faq page. It would be so much easier to introduce this feature if you could provide a function to which I could supply a node id and it would return something like what is currently returned by "theme_image_attach_teaser()" and "theme_image_attach_body()". I can't use these functions directly as it involves knowing the iid beforehand. I don't want to add code to my module that requires knowledge of the structure of the image_attach table which is the only way I know of getting the list of iids, so a function like this would be very handy. I think other modules integrating with image attach would also find this beneficial.

Cheers,
Stella