Documentation fix and improvements to XML configuration help res_pjsip_acl

Documentation fix and improvements to XML configuration help res_pjsip_acl

 *  One bug fix. Made the synopsis for "type" to accurate.
 *  changing the usage of "IP-domains" to "IP addresses"
 *  clarifying the usage for the options, by adding a relevant description for
    each
 *  modified other areas of the XML help for clarity, such as the module
    description and a few synopsis changes here and there. See the patch.

(issue ASTERISK-22458)
(closes issue ASTERISK-22458)
Reported By: Rusty Newton
Review: https://reviewboard.asterisk.org/r/2823/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@399017 65c4cc65-6c06-0410-ace0-fbb531ad65f3