Completely fixed "MySQL DataSource class missing" when trying to use MySQL database.
Added a new useful feature for admins: From now, you can modify the "Whitelist" section in config by using the GUI:
Command: /esadmin whitelist
Permission: exstorage.admin.command.whitelist
Tips: To add items, at first, you have to put it in your inventory, then re-open the GUI and click to the item you have put in. To remove, just click to the item you want on top inventory. It will be applied immediately for all players after adding/removing the item.
Added a new command, allowing the players to withdraw items without opening the GUI: