Jual beli tanah dengan kuasa jual yang telah berakhir demi hukum dan akibat hukumnya terhadap akta jual beli : studi kasus putusan nomor 29PK/PDT/2009 = The letter of authority of land transfering which had ended by the law and the legal consequences to the land deed legal : analysis of the Verdict number 29PK/PDT/2009