patch 7.4.1578
Problem:    There is no way to invoke a function later or periodically.
Solution:   Add timer support.
diff --git a/src/proto/screen.pro b/src/proto/screen.pro
index 6330fdc..aad8187 100644
--- a/src/proto/screen.pro
+++ b/src/proto/screen.pro
@@ -6,6 +6,7 @@
 void redraw_curbuf_later(int type);
 void redraw_buf_later(buf_T *buf, int type);
 int redraw_asap(int type);
+void redraw_after_callback(void);
 void redrawWinline(linenr_T lnum, int invalid);
 void update_curbuf(int type);
 void update_screen(int type);