Split logger.h into log_reader and log_writer

Much simpler!

Change-Id: I6c4ee363b56b67dac40c456261bbed79d01b8eb6
diff --git a/y2020/vision/viewer_replay.cc b/y2020/vision/viewer_replay.cc
index 82ab11a..234c445 100644
--- a/y2020/vision/viewer_replay.cc
+++ b/y2020/vision/viewer_replay.cc
@@ -3,7 +3,7 @@
 #include <opencv2/highgui/highgui.hpp>
 #include <opencv2/imgproc.hpp>
 
-#include "aos/events/logging/logger.h"
+#include "aos/events/logging/log_reader.h"
 #include "aos/events/simulated_event_loop.h"
 #include "aos/init.h"
 #include "y2020/vision/vision_generated.h"