Added ids to various chapters, and replaced "See Chapter <n>" in the text
with lots of <xref linkend="...">.

Note that the PPP examples have moved to /usr/share/examples/ppp.

Indent the example ppp.conf file properly.

Talk about the relationship between /etc/rc.conf and /etc/defaults/rc.conf.

PR: docs/18115
Submitted by: john@t-f-i.freeserve.co.uk

Update the path to the NT hosts file.

Submitted by: Brian Wilson <bwilson@powerinter.net>