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.
