move file attachments to sup-module

Hello

First, thank you very much for this great module. This is IMHO one of the top 10 modules
for drupal. Exellent.

I noticed when i worked with devel that the webfm file attachments hook is executed any
time a node is loaded even that module part is disabled (we don't need it).

Would it not be better, for installations not using the attachment part, to move that code to a sup
module someone must explicit activate in modules? In that way we would remove on query
from the workflow.