Log Message:
This adds a mk.conf setting for the xisp "dialer" group. I call it
"DIALER_GROUP" instead of "XISP_GROUP" as maybe it can be \ 
used for other
packages also later.

This is for PR pkg/19566.

Update MESSAGE to use LOCALBASE instead of X11BASE. (From
Manuel Bouyer)

And update MESSAGE to not hardcode the "group".

This also updates patch-ac because of conflicting types for fprintf and
printf. I don't know how this package built before on NetBSD recently.

Also this patch honors VARBASE and PKGMANDIR.

Thank you Manuel Bouyer for testing this.