add routine to return degree of a node.
add routine to return degree of a node.

virneo/relex,linas/relex,williampma/relex,williampma/relex,rodsol/relex,ainishdave/relex,williampma/relex,AmeBel/relex,rodsol/relex-temp,ainishdave/relex,linas/relex,rodsol/relex-temp,williampma/relex,opencog/relex,rodsol/relex-temp,anitzkin/relex,ainishdave/relex,leungmanhin/relex,anitzkin/relex,virneo/relex,leungmanhin/relex,opencog/relex,AmeBel/relex,anitzkin/relex,anitzkin/relex,virneo/relex,rodsol/relex-temp,rodsol/relex,rodsol/relex-temp,virneo/relex,ainishdave/relex,anitzkin/relex,linas/relex,AmeBel/relex,opencog/relex,leungmanhin/relex,rodsol/relex,rodsol/relex