Fixed display of single-line messages.
  Correctly handle nested MIME-parts.

  We iterate over every part as we did before, but now we also
 look for nested parts.

  This closes #56.

  As this was causing me pain I've made a new binary snapshot.
  Added utility for dumping messages.

  THis allows me to sanity-check MIME-code in one place.
  Build utilities, on-demand.  Clean them always.
  Added sample messages - both of which were the cause of bug
 reports.

  xen-list.msg = #56
  meetup.msg = #57
  Ignore the utility program the user might build.
  Decoded base64/quoted-printable message bodies in our test script.

  This updates #57.
  Decoded base64/quoted-printable message-bodies.

  Using the code from our test-script we can now show
 quoted-printable & base64 message-bodies.

  This fixes #57.