patch 7.4.1557
Problem: Windows cannot be identified.
Solution: Add a unique window number to each window and functions to use it.
diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index f5e0d19..7035f26 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -59,6 +59,7 @@
int list_append_tv(list_T *l, typval_T *tv);
int list_append_dict(list_T *list, dict_T *dict);
int list_append_string(list_T *l, char_u *str, int len);
+int list_append_number(list_T *l, varnumber_T n);
int list_insert_tv(list_T *l, typval_T *tv, listitem_T *item);
void list_insert(list_T *l, listitem_T *ni, listitem_T *item);
void vimlist_remove(list_T *l, listitem_T *item, listitem_T *item2);