Experience book

Added three books for storing experience.

• Experience book:
• Can store 10000 experience points;

• Experience book Plus:
• Can store 100000 experience points;

• Experience book Pro Max Plus:
• Can store infinite experience points;

Default Key Position:

• F key:Switching storage/retrieval mode;

• Right Click:Store/retrieve 10 experience points;

• Shift+Right Click:Store/retrieve 1000 experience points;

Synthetic method:

• Experience Book Plus:Experience Book+Upgrade Module Plus,Throw to the ground;

• Experience Book Pro Max Plus:Experience Book Plus+Upgrade Module Pro Max Plus,Throw to the ground.