update qunit for stdev and variance
update qunit for stdev and variance

cmpolis/jstat,NorthDecoder/jstat,jamescgibson/jstat,akrawitz/jstat,smarden1/jstat,smarden1/jstat,JeebsM/jstat,NorthDecoder/jstat,JeebsM/jstat,ggonzale/jstat,jstat/jstat,akrawitz/jstat,ggonzale/jstat,jstat/jstat