Patch adds all the packet and structure stuff to skinny to enable setting 
service URLs in skinny, such as corporate directories.

This stuff is only relevant during load/unload as when activated. Also 
some minor changes removing duplicated counting of addons and speedials in 
handle_skinny_show_devices.

Review: https://reviewboard.asterisk.org/r/2321/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@381718 65c4cc65-6c06-0410-ace0-fbb531ad65f3