Add 'user friendly' datastore API.

service/datastore/properties.go

Index: service/datastore/properties.go
diff --git a/service/rawdatastore/properties.go b/service/datastore/properties.go
similarity index 97%
rename from service/rawdatastore/properties.go
rename to service/datastore/properties.go
index 388afba8506d41c874c6e249bfd6c6c301a7f63f..d9a4907bd78d85ca4fc4c08030efae3d4d42776d 100644
--- a/service/rawdatastore/properties.go
+++ b/service/datastore/properties.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-package rawdatastore
+package datastore
 
 import (
 	"errors"
@@ -331,11 +331,18 @@ type PropertyLoadSaver interface {
 	Save(withMeta bool) (PropertyMap, error)
 
 	// GetMeta will get information about the field which has the struct tag in
-	// the form of `gae:"$<key>[,<value>]?"`.
+	// the form of `gae:"$<key>[,<default>]?"`.
 	//
-	// string and int64 fields will return the <value> in the struct tag,
-	// converted to the appropriate type, if the field has the zero value.
+	// Supported metadata types are:
+	//   int64  - may have default (ascii encoded base-10)
+	//   string - may have default
+	//   Toggle - MUST have default ("true" or "false")
+	//   Key    - NO default allowed
 	//
+	// Struct fields of type Toggle (which is an Auto/On/Off) require you to
+	// specify a value of 'true' or 'false' for the default value of the struct
+	// tag, and GetMeta will return the combined value as a regular boolean true
+	// or false value.
 	// Example:
 	//   type MyStruct struct {
 	//     CoolField int64 `gae:"$id,1"`
@@ -348,12 +355,6 @@ type PropertyLoadSaver interface {
 	//   // val == 10
 	//   // err == nil
 	//
-	// Struct fields of type Toggle (which is an Auto/On/Off) allow you to
-	// specify a value of 'true' or 'false' for the default value of the struct
-	// tag, and GetMeta will return the combined value as a regular boolean true
-	// or false value. If a field is Toggle, a <value> MUST be specified.
-	//
-	// Example:
 	//   type MyStruct struct {
 	//     TFlag Toggle `gae:"$flag1,true"`  // defaults to true
 	//     FFlag Toggle `gae:"$flag2,false"` // defaults to false