utils: Fix memory leaks and missed unregistration of CLI commands on shutdown

Final set of patches in a series of memory leak/cleanup patches by Corey Farrell

(closes issue ASTERISK-22467)
Reported by: Corey Farrell
Patches:
    main-utils-1.8.patch uploaded by coreyfarrell (license 5909)
    main-utils-11.patch uploaded by coreyfarrell (license 5909)
    main-utils-12up.patch uploaded by coreyfarrell (license 5909)
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Merged revisions 401829 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 401830 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 401831 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@401832 65c4cc65-6c06-0410-ace0-fbb531ad65f3