[milo] {buildbucket,buildbot,swarming,logdog} -> backends/*.

milo/appengine/job_source/buildbot/datastore.go

 // Copyright 2016 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package buildbot
 
 import (
         "github.com/luci/gae/service/datastore"
 
         "golang.org/x/net/context"
@@ skipping 35 matching lines @@
                         builds = append(builds, build)
                         tmpCursor, err := getCursor()
                         if err != nil {
                                 return err
                         }
                         nextCursor = &tmpCursor
                         return nil
                 })
         return builds, nextCursor, err
 }