Vim 8.1 release

Update version number and information.  Fix a couple of tests.
diff --git a/src/gui_w32.c b/src/gui_w32.c
index 25fbe9f..350b6fc 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -286,6 +286,8 @@
 typedef int LONG;
 typedef int WNDPROC;
 typedef int UINT_PTR;
+typedef int COLORREF;
+typedef int HCURSOR;
 #endif
 
 #ifndef GET_X_LPARAM