Install Spigot onto gentoo

(Personal memo) To build / upgrade / run Spigot on Gentoo linux.

cd /opt/Bukkit
wget https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar
java -jar BuildTools.jar --rev latest

/etc/init.d/spigot-server.fktn-spigot stop

cp -a spigot-n.n.n.jar spigot-server.jar
cd /var/lib/spigot-server/fktn-spigot
java -jar /opt/Bukkit/spigot-server.jar --forceUpgrade
---wait for a while---
> stop

chown minecraft:minecraft logs/*
/etc/init.d/spigot-server.fktn-spigot start