DoubleJump++

• Completely restructured the Code, DoubleJump 2.0
• Fixed falldamage bug, DoubleJump no longer conflicts with normal falldamage
• Commandstructure for /dj getitem changed to /dj item [player]
• Added optional player argument to /dj toggle [player] Ignores toggle cooldown
• doublejump.item.others & doublejump.toggle.others permission
• Velocity values in the config file now actually accept double values
• Added Gravity's great auto-updater, can be disabled in the config file

The fly commands only work for the player who typed it and for now, cannot be used with arguments(e.g. /fly <player> doesn't work). I won't change this because I cannot detect if the player has the permission to toggle flight for other players, but they could turn DoubleJump off for other players without permission if I would implement this feature.