make upgrade overwrites /etc/mail/mailer.conf

[Matthew Dillon]

:OK, instead of reinventing the wheel for the various config files,
:why can't we do a full three way merge?
:installworld installs into /var/db/etc/current. If the file doesn't
:exist in /etc, it goes there and into /var/db/etc/base. We provide
:a shell script which does a three way diff between /var/db/etc/base
:vs. /etc and /var/db/etc/base vs. /var/db/etc/current. If the user
:accepts / rejects the update, the entry from current is copied to
:base.
:
:Yes, this means some work for the initial time to set it up,
:but in the medium term makes handling e.g. of users and user stuff
:much easier, because there is only one place to add the necessary
:magic for updates -- the script.
:
:Joerg
    
    This seems like massive overkill to me.  While I don't mind the idea
    of using a database, I don't see a major necessity for it either.
    Eventually I would like to go to a services model for most of these
    files anyway (the CAPS stuff that hasn't been touched in a while).
    In the mean time it seem far more straightforward just to extend
    the existing code to checking two files instead of one using a 
    configuration model that everyone is already familiar with.

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>