QDict: Introduce functions to retrieve QDictEntry values

Next commit will introduce a new QDict iteration API which
returns QDictEntry entries, but we don't want users to directly
access its members since QDictEntry should be private to QDict.

In the near future this kind of data type will be turned into a
forward reference.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/qdict.h b/qdict.h
index dcd2b29..0c8de3c 100644
--- a/qdict.h
+++ b/qdict.h
@@ -34,6 +34,8 @@
 
 /* Object API */
 QDict *qdict_new(void);
+const char *qdict_entry_key(const QDictEntry *entry);
+QObject *qdict_entry_value(const QDictEntry *entry);
 size_t qdict_size(const QDict *qdict);
 void qdict_put_obj(QDict *qdict, const char *key, QObject *value);
 void qdict_del(QDict *qdict, const char *key);