pjsip_wizard.conf.sample: Add IP authentication and TLS examples.

pjsip_wizard.conf.sample: Add IP authentication and TLS examples.

The only ITSP example in the file shows a single trunk that registers and
authenticates.  Many providers, including DIDWW which motivated this
change, instead authenticate by IP address, deliver inbound calls from
several regional POPs, and terminate outbound calls through a separate
gateway that does require digest authentication.  Several things about
configuring that with the wizard are not obvious from the option
reference:

* remote_hosts alone generates the per-host identify matches, and is
  mandatory when registrations are not accepted.
* Inbound and outbound need one wizard each, because a wizard has a
  single remote_hosts list.
* A template carrying "type = wizard" is not turned into objects itself,
  so the two can share one.

TLS has a pitfall of its own: the wizard cannot create transport objects,
so the transport has to be defined in pjsip.conf and referenced here by
name, while media_encryption belongs to the endpoint and needs the
endpoint/ prefix.

Add commented-out examples for an IP authenticated trunk pair sharing a
template, and for a TLS trunk with SRTP.

No functional change.

UserNote: pjsip_wizard.conf.sample now includes examples for an ITSP that
authenticates by IP address and delivers calls from several hosts, and
for a TLS trunk with SRTP.