Use 4787c23dce0f5ac856d8d398225828971a93a3ff Guava patch for onlinePlayers

This change improves the quality of life for plugin developers using
iterator iteration with side-effects. In the specified Guava patch, the
internal iterator no longer relies on the AbstractList iterator which
iterates by index, and will instead wrap the provided iterator in a
transformer given the Function.
Update CraftBukkit to Minecraft 1.7.10
Rework damage modifiers into functions so Bukkit can call them.