Add new AMI and ARI events for connected line changes on a channel.

The AMI event is called NewConnectedLine and the ARI event is called
ChannelConnectedLine.

ASTERISK-24554 #close
Reported by Matt Jordan

Review: https://reviewboard.asterisk.org/r/4231



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@429064 65c4cc65-6c06-0410-ace0-fbb531ad65f3