Accessing members of struct ast_str outside of the string manipulation API
routines is invalid since struct ast_str is supposed to be treated as
opaque.

Review: https://reviewboard.asterisk.org/r/4194/
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Merged revisions 428244 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 428245 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 428246 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@428255 65c4cc65-6c06-0410-ace0-fbb531ad65f3