AO2: Add an assert for bad objects

This adds an assert that will only be active if Asterisk is compiled
with DO_CRASH and allows the testsuite to fail tests that would
otherwise require log file parsing.
........

Merged revisions 409566 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@409567 65c4cc65-6c06-0410-ace0-fbb531ad65f3