Fix several bugs; more still to come:
    - Plugin failing to compile on 1.7.2-R0.2 and lower (I will miss
you, JavaPlugin#getPlugin())
    - Fix arena class data collection
    - Fix arena info tracker
    - Fix arena-starting
    - Missing warps telling too many warps (due to duplicate storage
from Set->List)
    - Fix null AbilityHandler due to failed data collection
    - Fix config.yml reset bug on tab usage.