patch 8.0.1738: ":args" output is hard to read

Problem:    ":args" output is hard to read.
Solution:   Make columns with the names if the output is more than one line.
diff --git a/src/proto/version.pro b/src/proto/version.pro
index 568cf77..cd44e8b 100644
--- a/src/proto/version.pro
+++ b/src/proto/version.pro
@@ -3,6 +3,7 @@
 int highest_patch(void);
 int has_patch(int n);
 void ex_version(exarg_T *eap);
+void list_in_columns(char_u **items, int size, int current);
 void list_version(void);
 void maybe_intro_message(void);
 void intro_message(int colon);