Added per Arena Whitelist/BlackList (optional)

Some changes on Arena.java and Game.java
Changed some event: PlayerBreak and PlayerPlace

If a person insert -1 on whitelist/blacklist all block are
allowed/locked

Games without this optional configuration use the general config.

This is an example of the new system.yml structure.
These setting are optional and have to be added manually by the admin or maintainer.

version: 0
sg-system:
  arenano: 2
  arenas:
    '1':
      world: hg1
      x1: 40
      y1: 120
      z1: 40
      x2: -40
      y2: 40
      z2: -40
      enabled: true
      block:
        isWhitelist: false
        break:
        - 1
        - 2
        place:
        - 1
        - 2
    '2':
      world: hg2
      x1: 40
      y1: 99
      z1: 40
      x2: -40
      y2: 19
      z2: -40
      enabled: true
  lobby:
    spawn:
      world: hg2
      x: 0
      y: 125
      z: 0
    sign:
      set: true
    signno: 2
    signs:
      '1':
        id: 1
        world: lobby
        x1: 10
        y1: 126
        z1: 4
        x2: 10
        y2: 126
        z2: -4
      '2':
        id: 2
        world: lobby
        x1: 10
        y1: 127
        z1: 4
        x2: 10
        y2: 127
        z2: -4