Make the attachment selector add attachments, instead of replacing

If someone wants to submit a bug report or feature request with 2 or more attachments, the current flow to do this is to click "Browse..." and select all desired attachments in one go. This is pretty unintuitive because the way most websites handle this kind of workflow is you select one attachment at a time, it uploads, and you select another one and that also uploads. What this then results in is people trying to submit 2 or more attachments, one at a time, only to find that the very last attachment is the only one that got sent.

Let the attachment selector add items to attach, instead of replace. And add a little X next to each attachment item so users can remove attachments that were selected by mistake. I still prefer being able to select multiple attachments at once, so please do not restrict the workflow to single selection.