Server shutdown takes incredibly long time, trying to find causes

GriefPrevention 7.8, this build: http://build.yu8.me:8080/job/GriefPrevention/147/

Related: https://github.com/Tux2/GriefPrevention/commit/310e93352beba34c89bc35fdcda3f1867d8b19d1#L2R380

Upon server stop there is a very long slowdown, and a stream of logs http://i.imgur.com/hkXZhUk.jpg It’s not even the slowdown, it’s read timeout on the server and players never seeing a normal server closed screen (with message defined in `bukkit.yml`).

What we include is a series of tests (ignore my failed Maven commits, focus on Matej’s) which caused us to notice that despite having ~4200 claims in DB, it’s not DB timing that causes the server to freeze on stop and throw read timeouts.

I’m opening this for a discussion, devs to devs.