Originate: Make setting caller id on outgoing call use either name or number.

Previous code was requiring both name and number to be available.

Also restored a comment block on why caller id is also set on an outgoing
call leg in addition to connected line from earlier versions of Asterisk.
........

Merged revisions 400303 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@400304 65c4cc65-6c06-0410-ace0-fbb531ad65f3