CraftBukkit removed their implementation that caused this issue,
switching to Mojang's implementation which doesn't appear to share it. I
already removed the important bit in the last upstream merge, this is
just unused and unnecessary now. So we remove it.
Spigot has patched this issue inside MapIcon, meaning that we no longer need to maintain this patch; Spigots patch also fixes#668 in that it will verify the length of the array, as well as protect against a negative type value being fetched from the array. Only real change is that Spigots patch returns a MapIcon.Type.PLAYER, instead of the RED_MARKER as originally PR'd by Aikar.
per: a5f9077242 (commitcomment-20268968)
The break may of been skipping attempts at valid chunks. I thought break was the right abort, but maybe it is not.
Make it so a Treasure Map does not target a structure outside of the
World Border, where players are not even able to reach.
This also would help the case where a players close to the border, and one
that is outside happens to be closer, but unreachable, yet another reachable
one is in border that would of been missed.
