Various: bugfixes found via chaos

Using DEBUG_CHAOS several instances of a null
pointer crash, and one uninitialized variable
were uncovered and fixed.  Also added details
on why Asterisk failed to initialize.

Review: https://reviewboard.asterisk.org/r/4468/
........

Merged revisions 433064 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@433065 65c4cc65-6c06-0410-ace0-fbb531ad65f3