Feature request: Ignore files opened (as opposed to downloaded)

[mforkel]

The add-on includes an option to ignore files by file type. I think it would be nice to have an additional option to ignore all files opened in the browser instead of downloaded and stored locally. When I open a file in the browser I usually want to view it but not store it. If I store it later nevertheless, I still have the mechanisms of the OS to access the storage location.