Skelun's XP Reward System

- Fixed a major issue where Farming wasn't being counted;
- Substantial performance increase on multiplayer;
- Added [​Mud] and [​Muddy Mangrove Roots] to Blocks counted towards Digging;
- Added [​Cracked Stone Bricks], [​Cracked Nether Bricks], [​Packed Mud] and [​Sandstone] to Blocks counted towards Mining;
- Removed [​Sugar Cane] from Crops counted towards Farming;

I've revised the whole code and made all possible optimization

I've cranked up the exp gain!

Now you earn:
- From level 0 to level 9 → 12 exp
- From level 10 to level 19 → 15 exp
- From level 20 to level 29 → 21 exp
- From level 31 forward → 33 exp

As I have based the entire system around formulas,
I've also released a spreadsheet detailing how the XP and the Deltas are calculated:

docs.google.com/spreadsheets/d/1ja2UrwOSQU-HuBbu5GjIAst3xkR4ZdJTHHQBmAlbfy0/edit?usp=sharing

Bug fixes:
Fixed some bugs with traveling.
- Sometimes, when you reentered a world, you would keep receiving XP non-stop until some point;
- Sometimes your Traveling Counter would decrease temporarily when sprinting.

Changed the exp gain feedback:
- Spawning an exp orb particle was buggy, so I've changed to just a sound.