Bug Fixes:
- Kill buffs from swordsmanship and axemastery now require killing the enemy with a sword or axe respectively
- Potions of instant healing and harming should work better with the Potion Master perk (and not heal you to full)
- Shift clicking with a full inventory or pressing occupied hotbar slots when crafting armor no longer gives infinite experience
- Sprinting experience can no longer be afk'd by sitting in a boat
- Added a knockback limit to the double hit perk, should prevent "velocity too high" events from occuring
- Tracked blocks are now stored in a concurrent hashmap to prevent concurrent thread errors

Features:
- Added new command /frpg changeMultiplier [playerName] [amount] to change a player's multiplier (as opposed to setting it). This might be useable for temporary exp boosts.
- Added two new nodes to advancedConfig.yml, beginnerLevelUpMessageMaxLevel and customBegginerLevelUpMessage, used to the control the message that displays when new players level up for the first few times.

Misc:
- Added failsafe to AbilityLogoutTracker playerItem hashmap