Added a super hacky system to load/unload commands at runtime. Bukkit's command system is rather bad with completions, so those are broken.
(e9d8cf9b by matthew miller)
Migrate CraftBook Five to Piston (#1213)
* Initial work towards using Piston as a command system
* Try migrating the variables commands, they don't seem to register though
* Finish converting all existing commands over to Piston (9ba3abd4 by matthew miller)
