TeamDebugger: Implement post syscall event handling.

We now watch for file write syscalls in the target team. If they
constitute a write to either stdout or stderr, we attempt to capture the
output, and notify interested listeners accordingly.

src/apps/debugger/controllers/TeamDebugger.h

@@ -141,6 +141,8 @@ private:
 									ImageCreatedEvent* event);
 			bool				_HandleImageDeleted(
 									ImageDeletedEvent* event);
+			bool				_HandlePostSyscall(
+									PostSyscallEvent* event);
 
 			void				_HandleImageDebugInfoChanged(image_id imageID);
 			void				_HandleImageFileChanged(image_id imageID);