Fix bug: Attachment Previews of Incoming Mails
When we receive an E-Mail containing two attachments with the same name, only one is preview is visible (the cause of this problem is distinct from the problem of the Documents Directory mentioned in Issue #300). The problem lies in the fact that the attachments objects lack a unique identifier. The previews of the attachments are therefore done by using their filenames which are not unique. Some small changes in AttachmentsViewMain.swift
and DisplayProtocols.swift
should suffice to fix this.