Add 'relativenumber' patch from Markus Heidelberg.
diff --git a/src/proto/misc2.pro b/src/proto/misc2.pro
index 261ec82..5c4cc42 100644
--- a/src/proto/misc2.pro
+++ b/src/proto/misc2.pro
@@ -11,6 +11,7 @@
 int dec_cursor __ARGS((void));
 int dec __ARGS((pos_T *lp));
 int decl __ARGS((pos_T *lp));
+linenr_T get_cursor_rel_lnum __ARGS((win_T *wp, linenr_T lnum));
 void check_cursor_lnum __ARGS((void));
 void check_cursor_col __ARGS((void));
 void check_cursor __ARGS((void));