Add queue monitoring hints

This patch adds support for hints on a queue.  Hints can be added using
the nomenclature 'Queue:name', where name is the name of the queue being
monitored.

This nifty feature was done by Alec Davis.

Review: https://reviewboard.asterisk.org/r/1619

Reported by: Alec Davis
Tested by: alecdavis
patches:
  review1619.diff2 by alecdavis (license 585)
........

Merged revisions 373235 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@373239 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES

@@ -173,6 +173,7 @@ Queue
    be logged in the agent field for ADDMEMBER and REMOVEMEMBER queue events if a
    state_interface has been set.
 
+ * Add queue monitoring hints.  exten => 8501,hint,Queue:markq.
 
 SayUnixTime
 ------------------

apps/app_queue.c

@@ -2868,6 +2868,10 @@ static int join_queue(char *queuename, struct queue_ent *qe, enum queue_result *
 		ast_copy_string(qe->announce, q->announce, sizeof(qe->announce));
 		ast_copy_string(qe->context, q->context, sizeof(qe->context));
 		q->count++;
+		if (q->count == 1) {
+			ast_devstate_changed(AST_DEVICE_RINGING, "Queue:%s", q->name);
+		}
+
 		res = 0;
 		/*** DOCUMENTATION
 		<managerEventInstance>
@@ -3172,6 +3176,9 @@ static void leave_queue(struct queue_ent *qe)
 		if (current == qe) {
 			char posstr[20];
 			q->count--;
+			if (!q->count) {
+				ast_devstate_changed(AST_DEVICE_NOT_INUSE, "Queue:%s", q->name);
+			}
 
 			/* Take us out of the queue */
 			/*** DOCUMENTATION

configs/extensions.conf.sample

@@ -708,12 +708,16 @@ include => demo
 ;exten => 6600,hint,park:701@parkedcalls
 ;exten => 6600,1,noop
 ;
-
 ;To subscribe to the availability of a free member in the 'markq' queue.
 ;Note: '_avail' is added to the QueueName
 ;exten => 8501,hint,Queue:markq_avail
 ;exten => 8501,1,Queue(markq)
-
+;
+; You can also monitor the status of a queue by providing a hint for a
+; particular queue name.
+;exten => 8502,hint,Queue:markq
+;exten => 8502,1,Queue(markq)
+;
 ; Some other handy things are an extension for checking voicemail via
 ; voicemailmain
 ;