extended group-by, fixed matrix mult
extended group-by, fixed matrix mult

bzz/incubator-mrql,achyut/incubator-mrql,apache/incubator-mrql,fegaras/incubator-mrql,achyut/incubator-mrql,fegaras/incubator-mrql,Leemoonsoo/mrql,apache/incubator-mrql,bzz/incubator-mrql,Leemoonsoo/mrql