libyang CHANGE review header includes

The plugins_types.h was supposed only for implementing data type plugins
code, so I've removed it from libyang.h (now it is supposed to be
included explicitly).
diff --git a/src/printer_yang.c b/src/printer_yang.c
index 81aba85..0aeb6d5 100644
--- a/src/printer_yang.c
+++ b/src/printer_yang.c
@@ -19,12 +19,14 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "common.h"
 #include "compat.h"
 #include "log.h"
-#include "plugins_types.h"
+#include "out.h"
 #include "out_internal.h"
+#include "plugins_types.h"
 #include "printer_internal.h"
 #include "printer_schema.h"
 #include "tree.h"