Strip unneeded stuff

Requires Java 8

I was adding lots of unneeded code that was making the plugin overly complex.
It no longer requires NMS at all.

This release is fully tested and used in production by PhanaticMC.

Improve forcefield radius detection, and fix configuration

Fix the issue where the forcefield isn't where it is supposed to be.
Optional delay until entering spawn after combat tag ends.
Improve bandwidth usage. (for 1.8 - 1.8.8)

Add CombatTagPlus support

Internal changes to allow for plugins besides worldguard to be supported
CombatTagReloaded support removed

Open Source it

Initial open source release