renaming_4: gofix -r everything/but/src/pkg

R=rsc
CC=golang-dev
https://golang.org/cl/5338043
diff --git a/doc/codewalk/markov.go b/doc/codewalk/markov.go
index 959c2b1..cb28eb0 100644
--- a/doc/codewalk/markov.go
+++ b/doc/codewalk/markov.go
@@ -50,8 +50,8 @@
 	"flag"
 	"fmt"
 	"io"
+	"math/rand"
 	"os"
-	"rand"
 	"strings"
 	"time"
 )
diff --git a/doc/codewalk/pig.go b/doc/codewalk/pig.go
index 9e415f5..b3f02af 100644
--- a/doc/codewalk/pig.go
+++ b/doc/codewalk/pig.go
@@ -6,7 +6,7 @@
 
 import (
 	"fmt"
-	"rand"
+	"math/rand"
 )
 
 const (
diff --git a/doc/codewalk/urlpoll.go b/doc/codewalk/urlpoll.go
index b320eb1..1439e34 100644
--- a/doc/codewalk/urlpoll.go
+++ b/doc/codewalk/urlpoll.go
@@ -5,8 +5,8 @@
 package main
 
 import (
-	"http"
 	"log"
+	"net/http"
 	"time"
 )