Fixed placeholders for PlaceholderAPI
Fixed the towers delete command and build command
Fixed an error that occured when right clicking summoned enemies in gui
Fixed a bug where players could buy red zombies -> earn coins -> buy a blue zombie or something else -> Sell red zombies for no loss (Since no coins) then buy red zombies again and repeat
Fixed super bomber upgrade price
Made the AI summon fill more safe (server side)
Added a button in tower menu to view its range
Decreased the default length of hard & expert difficulties
Increased default difficulty for enemies in waves 20+