MID/BID generation is inconsistent

[Jeremy Cooper]

Always assign a MID to ALL messages generated here, not just bulletins.
Check all incoming traffic for a MID, not just bulletins.

If a message has no MID and is being forwarded here, don't generate one here.
As is, the BBS acts as if a forwarded message is being created here by a user.
Messages forwarded here by a BBS are not created by a user--need to keep track
of that.