Huge update with almost all features now functional.

Changelog
+ Added custom shop functionality
+ Added persistent rewards (crystals) and permanent kits
+ Added functionality for dynamic mob count, dynamic difficulty, dynamic prices, dynamic wave time limit, and difficulty multiplier
+ Added difficulty labeling for arenas
+ Added functionality to copy settings from another arena or from presets
+ Added sound and particle effects
+ Added commands to purchase kits and modify player crystal balance
+ Added ability to customize server messages or make translations

* Spawn tables are now separate from the config file and can be customized per arena
* Default spawn table readjusted, going up to wave 40
* Gems are now invulnerable to explosions
* Closed arenas no longer show player or spectator count
* Command to edit arenas changed from /vd to /vd admin
* Rebalanced pricing on potions
* Minor UI readjusting
* Many bug fixes
* Updated configs and data file structures to reflect changes