core: event parsing enahced for dialog;ma

- event defined by draft-anil-sipping-bla for Multiple Line Appearances,
folloing to Shared/Bridged Line Appearances (SLA, BLA)
- draft is defunct but still some implementations out there
(cherry picked from commit 1e99795d2ddebe8a6794c3b407f96d30378b872f)

parser/parse_param.c

@@ -99,6 +99,15 @@ static inline void parse_event_dialog_class(param_hooks_t* h, param_t* p)
 			h->event_dialog.sla = p;
 		}
 		break;
+
+	case 'm':
+	case 'M':
+		if ((p->name.len == 2) &&
+		    (!strncasecmp(p->name.s + 1, "a", 1))) {
+			p->type = P_MA;
+			h->event_dialog.ma = p;
+		}
+		break;
 	}
 }
 

parser/parse_param.h

@@ -61,7 +61,8 @@ typedef enum ptype {
 	P_FROM_TAG,  /* Dialog event package: from-tag */
 	P_TO_TAG,    /* Dialog event package: to-tag */
 	P_ISD,       /* Dialog event package: include-session-description */
-	P_SLA        /* Dialog event package: sla */
+	P_SLA,       /* Dialog event package: sla */
+	P_MA         /* Dialog event package: ma */
 } ptype_t;
 
 
@@ -121,6 +122,7 @@ struct event_dialog_hooks {
 	struct param* to_tag;
 	struct param* include_session_description;
 	struct param* sla;
+	struct param* ma;
 };
 
 /*