All new command messages style (much better and simpler) for all configurations by @Heliossss
This version is not compatible with any previous version (some placeholders and setup changed)
Database has not been changed
No gui
New API events PlayerKillStreakEvent and PlayerKillStreakTopEvent
New placeholders for PlaceholderAPI that will return last got xp/lost/item_boost/type killed
%pvplevels_xp_type%
%pvplevels_xp_get%
%pvplevels_xp_lost%
%pvplevels_xp_item%​