add definition of new parameter style 	... T for trailing arguments of type T.
add definition of new parameter style
	... T
for trailing arguments of type T.

R=rsc, gri, ken2, iant
CC=golang-dev
http://codereview.appspot.com/194100
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go