Support for Spigot 1.9 and more!

New: added support for item metadata in break, place and craft achievements (thanks to CryLegend for his contribution)! See default config (log_2:1) for syntax example.
Improvement: added support for Minecraft 1.9! If you are using older versions of Minecraft, don't worry, this version is compatible with them, please update! If you find a bug with Minecraft 1.9, please open a report on the issue tracker.
Improvement: yet again heavy work on performance.
Fix: fixed maximum level achievements that were not tracking levels accurately.
Other: various other improvements and fixes.