Add support for RFC 4662 resource list subscriptions.

This commit adds the ability for a user to configure
a resource list in pjsip.conf. Subscribing to this
list simultaneously subscribes the subscriber to all
resources listed. This has the potential to reduce
the amount of SIP traffic when loads of subscribers
on a system attempt to subscribe to each others' states.



git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@420384 f38db490-d61c-443f-a65b-d21fe96a405b
Ensure bridges exist when trying to determine bridged parties when publishing transfer information.
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Merged revisions 420387 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@420388 f38db490-d61c-443f-a65b-d21fe96a405b