MXS-1220: Fix resource self links

The top level resource self links pointed to the collection instead of the
resource itself. The individual resoures now also have a links field that
contains the self link to the resource. This should make navigation of the
API easier as all objects have valid links in them.

server/core/load_utils.cc

@@ -453,6 +453,7 @@ static json_t* module_json_data(const LOADED_MODULE *mod, const char* host)
 
     json_object_set_new(attr, CN_PARAMETERS, params);
     json_object_set_new(obj, CN_ATTRIBUTES, attr);
+    json_object_set_new(obj, CN_LINKS, mxs_json_self_link(host, CN_MODULES, mod->module));
 
     return obj;
 }