libyang REFACTOR config.h code split

... into compat.h and version.h.
diff --git a/src/tree_schema_free.c b/src/tree_schema_free.c
index 22843af..3352134 100644
--- a/src/tree_schema_free.c
+++ b/src/tree_schema_free.c
@@ -14,8 +14,8 @@
 
 #include <stdlib.h>
 
+#include "compat.h"
 #include "common.h"
-#include "config.h"
 #include "plugins_exts.h"
 #include "plugins_types.h"
 #include "tree.h"