BUG #8171: Log messages lacking enough details

The following bug has been logged on the website:

Bug reference:      8171
Logged by:          Trond Endrest=C3=B8l
Email address:      Trond.Endrestol@ximalas.info
PostgreSQL version: 9.2.4
Operating system:   FreeBSD/amd64 9.1-STABLE r250805
Description:        =


The log message:

LOG:  could not bind IPv6 socket: Can't assign requested address

should be augmented to reveal the attempted address, thus making the lives
of us poor db admins a lot easier. Likewise for any similar IPv4 related log
messages.

In fact all kinds of log/warning/error messages should be to the point and
include all(!) relevant details and not just a vague description of what
happened.

The above log message was due to the file /etc/hosts containing the two
lines:

localhost fe80::1
localhost fe80:2::1

Changing these two lines to:

localhost-6ll fe80::1
localhost-6ll fe80:2::1

made PostgreSQL much happier.