Minecraft wiki entry for Development_versions, associated text: MC-250 – Ender Dragon can still grief stuff like cobblestone and chests even if the gamerule mobGriefing is set on false.
MC-4577 – Unable to combine enchanted books for a higher level enchant.
MC-6705 – If the player use an external editing tool (MCEdit) to give an enchanted book with multiple enchantments, and said player tries to combine it with an item, it will only enchant it with the first enchantment on the list.