Add support for DPMA to autosupport

This adds the ability to get the DPMA version, a listing of the local
firmware directory, and indexes of configured remote directories.

(closes issue AST-1070)
Reported By: Malcolm Davenport
Tested By: Kinsey Moore <kmoore@digium.com>


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@380004 65c4cc65-6c06-0410-ace0-fbb531ad65f3