- Added 1.14 support

- Fixed debug message...

- New feature: you can teleport players back to overworld or to the lobby when the dragon is killed.
if 'respawnplayers' is set to true and 'resetworld' is false the players in end-world will get teleported after the countdown ('resetworlddelay').
Players will be teleported to overworlds spawn (f.e. myworld_the_end --> myworld)
If 'respawncommand' in config is set, this command will get used instead of the default teleport.
You can use this for anything, like teleporting to another world: 'mvtp $player anotherworld'
or teleporting to any place in the end world, etc...
One minute before the command is executed there will be a broadcast! Change this by editing 'playerrespawn'

- Added a way for displaying the remaining time to next dragon respawn by using PlaceholderAPI: %dragonslayer_timer%
This placeholder will return 'worldname: time' (in minutes).