handle querying of undefined or unset variables - use null rather than #f for javascript and json compatibility
handle querying of undefined or unset variables - use null rather than #f for javascript and json compatibility

inflector/opencog,yantrabuddhi/opencog,inflector/opencog,yantrabuddhi/opencog,inflector/opencog,AmeBel/opencog,andre-senna/opencog,shujingke/opencog,shujingke/opencog,misgeatgit/opencog,misgeatgit/opencog,shujingke/opencog,andre-senna/opencog,shujingke/opencog,misgeatgit/opencog,misgeatgit/opencog,inflector/opencog,ruiting/opencog,AmeBel/opencog,andre-senna/opencog,ruiting/opencog,ruiting/opencog,ruiting/opencog,misgeatgit/opencog,ruiting/opencog,yantrabuddhi/opencog,inflector/opencog,yantrabuddhi/opencog,AmeBel/opencog,misgeatgit/opencog,AmeBel/opencog,inflector/opencog,AmeBel/opencog,misgeatgit/opencog,AmeBel/opencog,ruiting/opencog,shujingke/opencog,shujingke/opencog,misgeatgit/opencog,andre-senna/opencog,AmeBel/opencog,yantrabuddhi/opencog,andre-senna/opencog,inflector/opencog,andre-senna/opencog,yantrabuddhi/opencog,inflector/opencog,shujingke/opencog,yantrabuddhi/opencog,andre-senna/opencog,misgeatgit/opencog,ruiting/opencog