Address review board feedback from Matt and Richard

* Remove extraneous whitespace
* Bump up debug levels of messages and add identifying info to messages.
* Account for potential failures of ao2_link()
* Add additional test and some more test data
* Add some comments in places where they could be useful
* Make threadpool listeners and their callbacks optional



git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@378652 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/taskprocessor.c

@@ -38,7 +38,6 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/cli.h"
 #include "asterisk/taskprocessor.h"
 
-
 /*!
  * \brief tps_task structure is queued to a taskprocessor
  *
@@ -560,6 +559,9 @@ struct ast_taskprocessor *ast_taskprocessor_create_with_listener(const char *nam
 	ao2_ref(p, +1);
 	listener->tps = p;
 
+	/* Allocation of private data must come after setting taskprocessor parameters
+	 * so that listeners who rely on taskprocessor data will have access to it.
+	 */
 	listener->private_data = listener->callbacks->alloc(listener);
 	if (!listener->private_data) {
 		return NULL;