Log queue member name when state_interface is set for ADDMEMBER and REMOVEMEMBER events

app_queue logs the events ADDMEMBER and REMOVEMEMBER with the agent field set
to the interface value rather than the membername value when a member is added
with a state_interface value set.  However all other member related queue
events are logged with the membername when a state_interface is set.  This
patch makes these fields optionally more consistent and correct.

(closes issue ASTERISK-14769)
Review: https://reviewboard.asterisk.org/r/1286


Patch-by: Jamuel Starkey
Tested-by: Kinsey Moore <kmoore@digium.com>


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@331037 65c4cc65-6c06-0410-ace0-fbb531ad65f3