Add a test suite event to indicate when the atxfer 3-way feature is detected

This adds a test suite event that indicates to tests when the attended transfer
three-way call feature is detected.

Review: https://reviewboard.asterisk.org/r/2912/
........

Merged revisions 401578 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@401580 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/bridge_channel.c

@@ -1092,6 +1092,7 @@ static void testsuite_notify_feature_success(struct ast_channel *chan, const cha
 #ifdef TEST_FRAMEWORK
 	char *feature = "unknown";
 	struct ast_featuremap_config *featuremap = ast_get_chan_featuremap_config(chan);
+	struct ast_features_xfer_config *xfer = ast_get_chan_features_xfer_config(chan);
 
 	if (featuremap) {
 		if (!strcmp(dtmf, featuremap->blindxfer)) {
@@ -1106,6 +1107,8 @@ static void testsuite_notify_feature_success(struct ast_channel *chan, const cha
 			feature = "automixmon";
 		} else if (!strcmp(dtmf, featuremap->parkcall)) {
 			feature = "parkcall";
+		} else if (!strcmp(dtmf, xfer->atxferthreeway)) {
+			feature = "atxferthreeway";
 		}
 	}