Added Multiple permissions.

[apachezy]

Sometimes we need to judge multiple permissions, we can write nodes like this:

upgrad-to-vip2:
  MATERIAL: diamond
  POSITION-X: 2
  POSITION-Y: 1
  NAME: '&eVIP2'
  LORE:
    - 'Upgrade from vip1 to vip2.'
    - '1. You can ...'
    - '2. You can ...'
  ACTIONS:
    - 'console: lp user {player} promote track1'
    - 'broadcast: Congratulations to {player} for upgrading to VIP2.'
  PERMISSIONS:
    - 'myserver.vip1'     # Must have vip1 to upgrade vip2
    - '-myserver.vip2'    # If it is already vip2, it cannot be upgraded.
  PERMISSION-MESSAGES:
    - 'Hey, {player}, you must be vip1 to upgrade to vip2.'
    - 'Hey, {player}, you are already vip2, please do not upgrade repeatedly.'

[apachezy]

Sorry, I accidentally deleted the created branch, which caused the RP to be closed. Now I restored the branch and resubmitted the RP here. Please review.

[filoghost]

Sorry, I'm officially putting this plugin in maintenance-only mode. I already didn't have enough free time, I should have done it earlier.