[imp] handling semicolon separated addresses

[Russell J. Lahti]

Quoting Eric Jon Rostetter <eric.rostetter@physics.utexas.edu>:
> True (and actually, it should, but not many people ever use this
> format, so it is very minor defect.  I don't consider this a real
> problem, and it probably isn't work fixing...)

Much agreed.  When used correctly, a message in your inbox is
displayed correctly and does not produce errors (although it is
displayed a little bit strange.)  Outgoing mail in that format
doesn't work through IMP, but as far as I'm concerned, that is
what the bcc field is used for.

-Russell