Fix various problems detected with Valgrind.

* chan_console accessed pvts after deallocation.
 * cdr_mysql stored a pointer that was freed by realloc()
 * The module loader did not check usecount on shutdown, which led to chan_iax2
 reading a timer that was already unloaded.
 * The event subsystem sometimes creates an event with no IEs.  Due to a corner
 condition, the code would read beyond the memory boundary.
 * res_pktccops did not correctly check whether its monitor thread was started.
(closes issue #16062)
 Reported by: alexanderheinz
 Patches: 
       20091109__issue16062.diff.txt uploaded by tilghman (license 14)
 Tested by: tilghman


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@228798 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_console.c

@@ -1500,6 +1500,7 @@ return_error_pa_init:
 return_error:
 	if (pvts)
 		ao2_ref(pvts, -1);
+	pvts = NULL;
 	pvt_destructor(&globals);
 
 	return AST_MODULE_LOAD_DECLINE;