Made broadcasting of affine transform more efficient
Made broadcasting of affine transform more efficient

Abasyoni/dynet,mitchellstern/dynet,Peilun-Li/dynet,cherryc/dynet,mitchellstern/dynet,Peilun-Li/dynet,cherryc/dynet,Abasyoni/dynet,Abasyoni/dynet,Peilun-Li/dynet,kamigaito/cnn,kamigaito/cnn,cherryc/dynet