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.


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/1.8@409566 f38db490-d61c-443f-a65b-d21fe96a405b