Implement the defined PUBLISH ESC API within res_sip_pubsub.

(closes issue ASTERISK-21452)

Review: https://reviewboard.asterisk.org/r/2630/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@393262 f38db490-d61c-443f-a65b-d21fe96a405b
Nothing to see here, move along.


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@393264 f38db490-d61c-443f-a65b-d21fe96a405b