Merge changes from team/russell/console_devices

 - Add support for multiple devices.  All devices are configured in console.conf.
 - Add "console list devices" CLI command to show configured devices.  Also, changed
 the old "list devices" to be "list available", which queries PortAudio for all
 audio devices that are available for use.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@99227 65c4cc65-6c06-0410-ace0-fbb531ad65f3