[ale] Sharing serial ports

[Alex Carver]

Finally got my replacement mail server up and running (not too bad, just
as fast as the old P2 :) ).

Anyone have an idea on how to share a serial port with two services?
I've got one modem that I want to use for faxing (via hylafax) and
caller ID reception (via ncid).  However, the two of them fight with
each other for the serial port.  For some reason I was thinking they
could share since they don't need to write to the modem at the same
time, only listen to the data (to pick up the CID data or decide when to
answer).