go/printer: changed max. number of newlines from 3 to 2

manual changes in src/pkg/go/printer, src/cmd/gofix/signal_test.go
(cd src/cmd/gofix/testdata; gofmt -w *.in *.out)
(cd src/pkg/go/printer; gotest -update)
gofmt -w misc src

runs all tests

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4715041

src/pkg/json/decode.go

@@ -71,7 +71,6 @@ type Unmarshaler interface {
 	UnmarshalJSON([]byte) os.Error
 }
 
-
 // An UnmarshalTypeError describes a JSON value that was
 // not appropriate for a value of a specific Go type.
 type UnmarshalTypeError struct {
@@ -742,7 +741,6 @@ func (d *decodeState) objectInterface() map[string]interface{} {
 	return m
 }
 
-
 // literalInterface is like literal but returns an interface value.
 func (d *decodeState) literalInterface() interface{} {
 	// All bytes inside literal return scanContinue op code.