Fix reference and container leaks when running 'astobj2 test.'

Fix reference and container leaks when running 'astobj2 test.'

We need to make sure that ao2_iterator_destroy is called once for each time that
ao2_iterator_init is called.  Also make sure to unref a newly allocated object
that we've linked into a container.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@298345 65c4cc65-6c06-0410-ace0-fbb531ad65f3