v1.5.0 : xAdmin2 compatibility

xAdmin2 compatibility

I have implemented xAdmin2's commands for managing levels and XPs of players, listed below:

• lsaddxp <player> <amount>: Add amount XP to player
• lsaddlvl <player> <amount>: Add amount LVL to player
• lssetxp <player> <amount>: Set player's XP to amount
• lssetlvl <player> <amount>: Set player's LVL to amount