Refactor serialization helpers from impl/memory -> service/datastore/serialize

impl/memory/datastore_query_test.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package memory
 
 import (
         "bytes"
         "testing"
 
@@ skipping 27 matching lines @@
                 }
 
                 post.SetInvert(col.Descending)
                 if err := serialize.WriteIndexColumn(pre, col); err != nil {
                         panic(err)
                 }
                 if err := serialize.WriteProperty(post, serialize.WithoutContext, prop(v)); err != nil {
                         panic(err)
                 }
         }
-        return queryCursor(bjoin(pre.Bytes(), post.Bytes()))
+        return queryCursor(serialize.Join(pre.Bytes(), post.Bytes()))
 }
 
 type queryTest struct {
         // name is the name of the test case
         name string
 
         // q is the input query
         q *dstore.Query
 
         // err is the error to expect after prepping the query (error, string or nil)
@@ skipping 110 matching lines @@
                                         So(err, ShouldErrLike, tc.err)
 
                                         if tc.equivalentQuery != nil {
                                                 So(rq, ShouldResemble, tc.equivalentQuery)
                                         }
                                 })
                         }
                 })
         })
 }