merge from main branch.
merge from main branch.

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