exp/norm: reverting to using strings.Repeat, as it doesn't look like exp/regexp is going to support returning multiple matches for a single repeated group.
exp/norm: reverting to using strings.Repeat, as it doesn't look like exp/regexp
is going to support returning multiple matches for a single repeated group.

R=r, rsc, mpvl
CC=golang-dev
http://codereview.appspot.com/5014045

h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang,h8liu/golang