Bug 851124 - [E-Mail] uplift all email to v1.0.1

Made the following changes:

- in message-cards.js, the regexp that whitelists mime types should be reduced
  to only include image types because audio will not be supported by the audio
  app.  So the clause for "/^audio\//.test(attachment.mimetype)" should go away.

- in compose-cards.js, the onAttachmentAdd method should not be added as a
  click listener to .cmp-attachment-container nodes.  Likewise, the '+' to add
  an attachment should not be visible, so the cmp-attachment-add node should
  either be removed or marked collapsed.