More file attach types

Hi, I like the work done in ~~#14~~ to use file paths instead of storing objects but I'm having a problem with the absolute file path. I wanted to use a zip file install on a flash drive, with all the attachments on the drive too. Because the path may change, this won't work.

Can the file attachment be modified to accept more general things like relative paths and web addresses?

I'm using 2.7.0 right now -thanks! 😀