Only complete EAS message after the third header.

We need three complete message headers before we deam a EAS message a
confirmed.  We still need to take 2 of 3 chars from each message as the
actual data.
Use best two of three characters for msg stream.

Wrap the actual EAS message from after the complete third header to the
beginning of the end of message stream with some helper functions.  This
will allow "processing" of the message text and message audio.