move definition of json_object_iter to public header to enable external use of json_object_object_foreachC

Patch from Rick Moran <https://github.com/DrHayt>


git-svn-id: http://svn.metaparadigm.com/svn/json-c/trunk@74 327403b1-1117-474d-bef2-5cb71233fd97

json_object.h

@@ -27,6 +27,14 @@ extern "C" {
 extern const char *json_number_chars;
 extern const char *json_hex_chars;
 
+/* CAW: added for ANSI C iteration correctness */
+struct json_object_iter
+{
+	char *key;
+	struct json_object *val;
+	struct lh_entry *entry;
+};
+
 /* forward structure definitions */
 
 typedef int boolean;