Bukkit/CraftBukkit — pull request #598 by dredhorse (2011-12-15 22:13:18+00:00)
Title: Should fix getHighestBlockYAt returning 0 in most cases

Checks if chunk is loaded and if not loads the chunks, but DOESN'T generate it.
returns y = 0 if chunk doesn't exist, as the underlying method will return 0 if the chunk isn't loaded.
fixes https://bukkit.atlassian.net/browse/BUKKIT-327