launch_daemon: Added support for external events.

* Other apps can register events, and the launch_daemon can act on them
  when they are triggered.

headers/private/app/LaunchDaemonDefs.h

@@ -22,12 +22,15 @@ namespace BPrivate {
 #define B_LAUNCH_DAEMON_PORT_NAME "system:launch_daemon"
 
 
-// message constants
+// Message constants
 enum {
 	B_GET_LAUNCH_DATA			= 'lnda',
 	B_LAUNCH_TARGET				= 'lntg',
 	B_LAUNCH_SESSION			= 'lnse',
 	B_REGISTER_SESSION_DAEMON	= 'lnrs',
+	B_REGISTER_LAUNCH_EVENT		= 'lnre',
+	B_UNREGISTER_LAUNCH_EVENT	= 'lnue',
+	B_NOTIFY_LAUNCH_EVENT		= 'lnne',
 };
 
 

headers/private/app/LaunchRoster.h

@@ -30,12 +30,21 @@ public:
 
 			status_t			StartSession(const char* login);
 
+			status_t			RegisterEvent(const BMessenger& source,
+									const char* name);
+			status_t			UnregisterEvent(const BMessenger& source,
+									const char* name);
+			status_t			NotifyEvent(const BMessenger& source,
+									const char* name);
+
 	class Private;
 
 private:
 	friend class Private;
 
 			void				_InitMessenger();
+			status_t			_UpdateEvent(uint32 what,
+									const BMessenger& source, const char* name);
 
 private:
 			BMessenger			fMessenger;