[MlMt] Content-type header viewing behaviors

[Benjamin Coddington]

Hi Benny, et al.

Something's changed out in my mail world recently such that emails of
plain-text patches for development work that used to arrive with:

Content-Type: text/plain; charset="US-ASCII"; x-default=true

Now arrive with:

Content-Type: application/octet-stream; x-default=true

This causes my MM (1.13.2 (5673)) to forego displaying the body, and only
presents the attachment dialog.  I'd love to be able to override this
behavior, if possible.  Is there a way to do that?

Ben