dict CHANGE split dictionary API to private and public part

Make part of the dictionary API public and usable by library users.
It should allow more effective way of memory usage.
diff --git a/src/resolve.c b/src/resolve.c
index b27f592..778a09b 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -31,7 +31,7 @@
 #include "resolve.h"
 #include "common.h"
 #include "xpath.h"
-#include "dict.h"
+#include "dict_private.h"
 #include "tree_internal.h"
 
 /**