Some Entities/BlockEntities don't store item data correctly

• Renamed saddles do not keep their name when used on pigs - note that horses do not exhibit this behavior
• Renamed plants lose their name when placed and retrieved from flower pots - note that a similar issue for jukeboxes was fixed: MC-116
• Renamed leads lose their name when used and collected
• Chest on mule or donkey
• Renamed containers such as chests do not keep their name when mined (Fixed in 16w35a)