patch 8.1.2013: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.
diff --git a/src/version.c b/src/version.c
index fee4ea3..d86f9f5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2013,
+/**/
     2012,
 /**/
     2011,