add -l flag to hg gofmt. don't apply gofmt to non-go files during upload check.
add -l flag to hg gofmt.
don't apply gofmt to non-go files during upload check.

R=r
http://go/go-review/1016048
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go