The display name includes formatting such as item hover event, display name (in italics if renamed in anvil), and color based on rarity.
This is what vanilla uses for give command feedback, and when an item is shown in a death message.
Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
Bukkit Changes:
e461dcfe #555: Item - add getters/setters for owner/thrower
CraftBukkit Changes:
055870c4 #758: Item - add getters/setters for owner/thrower