Fix segfault

* Gearmand would segfault if you submitted an epoch job while using Postgres
  as the persistent queue
When an exception is thrown we should remove job from the server.
Encapsulate failed packet.
GEARMAN_TASK_STATE_EXCEPTION was not in the correct position (which would have been harmless).
Fix to determine location of Redis server.
Merge trunk.
Fix for callback around exception.
Fix for clang compiler issue.
Merge with trunk.
Final set of patches from laptop.
Update m4.
Fix case where we are not passing warnings.`
Update bootstrap.sh
Merge lp:~brianaker/gearmand/update-bootstrap-june Build: jenkins-Gearmand-653
Fix for cases where we might get zero.
Merge lp:~brianaker/gearmand/update-bootstrap-june Build: jenkins-Gearmand-655
Merge lp:~brianaker/gearmand/update-bootstrap-june Build: jenkins-Gearmand-656
Merge lp:~brianaker/gearmand/m4-updates-june Build: jenkins-Gearmand-657
Partial merge/fix.
Merge lp:~brianaker/gearmand/fix_segfault Build: jenkins-Gearmand-658