#33 InputDataStreamAdapter doesn't handle msgs w/o a MIME header

[Wladimir Araujo]

This class expects a message that explicitly declares a
MIME header (ContentType). If that is not the case, the
result is sometimes an empty stream. That depends on
the message content itself.
Per spec, when a MIME header is not specified, it must
assume a default (application/octet-stream).
The problem is that the class searches for a ':'. It
should, instead, do a proper MIME parsing.