LiteSell - /sell /sellall /worth + GUI v1.5.9

1. ADDED A NEW LICENSE SYSTEM, request a new license key first before adding the plugin.
2. Fixed the issue with /sellall and shulkers.

1. Fixed the /sellall returning double the items.

1. Made it so you can transfer data from database to file system or from file system to database.

/sell transferdata

1. Updated the inventory framework with the security checks.

1. Now return unsellable items even if it doesn't even contain 1 sellable item.
2. Now remove the worth lore completely from creative.
3. Added an optional "unsellable items" detected message.
4. Updating the data on server shut down, not only on quit.

1. Made it to work on older Minecraft versions.

1. Made it so enchanted book values are based on enchantments-value.yml.
2. Made it so the global event boost to apply to /sellall and /sellhand all.
3. Fixed /sellall so it values the items correctly.
4. Fixed /sellhand all to value the items correclty.

1. Added world blacklist, not being able to use sell in a specific world. (Suggested by TheWixaj)