vis: try to reduce number of redraws

This is a not yet successful attempt to reduce terminal flickering
when resizing windows as is for example the case when entering
command mode.

UI related debug output can be enabled with:

 $ make CFLAGS=-DDEBUG_UI=1
 $ ./vis > log

1 files changed, 1 insertions, 1 deletions

diff --git a/vis-core.h b/vis-core.h
index 51c9447..9e3c4f1 100644
--- a/vis-core.h
+++ b/vis-core.h
@@ -197,7 +197,7 @@ void action_reset(Action*);
 void mode_set(Vis *vis, Mode *new_mode);
 
 void window_selection_save(Win *win);
-Win *window_new_file(Vis *vis, File *file);
+Win *window_new_file(Vis*, File*, enum UiOption);
 
 const char *file_name_get(File*);
 void file_name_set(File*, const char *name);