Cleanup logger on exit.

Cleanup logger on exit.

* Cleanup CLI commands, destroy verbosers and logchannels lists on exit.

(issue ASTERISK-20649)
Reported by: Corey Farrell
Patches:
      logger-cleanup-all.patch (license #5909) patch uploaded by Corey Farrell
      Modified
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Merged revisions 377771 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 377772 from http://svn.asterisk.org/svn/asterisk/branches/10

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@377773 65c4cc65-6c06-0410-ace0-fbb531ad65f3