[+] Fix generators fading (e.g when generator is coral and doesn't have water, it will be faded).
[+] Add placeholder and permission requirements to place or upgrade generators, this is useful if you want to make generators upgradeable on certain "levels" for player for example.
[+] Add world multiplier for generators.
[+] Add %nextgens_event_isactive% that will return "true" or "false"
[+] Prevent generators from decaying (leaves).
[+] Add PlaceholderAPI support for generator item, sellwand, and items on all gui.