Score tag in books doesn't work with cheats off/ as non-op

The bug

The score-tag in a book does not work, if you /give it to someone who is not an operator or, in a singleplayer world, if cheats are disabled. Video demonstrating the issue: http://youtu.be/QTfumET7Apo

How to reproduce

1. Start a world with cheats off
2. Open the world in LAN and and set 'allow cheats' to ON
3. /give yourself a command block and insert the command below
4. Reopen your world
5. Activate the command block. You should now get a book that shows the JSON-text instead of the score.

Alternatively, you can test it on a server if you deop yourself after you entered the following command

/give @a written_book{
	title:"Test",
	author:"Test",
	pages:
	[
		"{
			\"text\":\"\",
			\"bold\":true,
			\"extra\":
			[
				{
					\"score\":
					{
						\"name\":\"@p\",
						\"objective\":\"Test\"
					}
				}
			]
		}"
	]
}