Support multiple versions of minecraft

CombatTag now supports minecraft 1.7.9, 1.7.10, 1.8, and 1.8.3.
CombatTag now has support for the spigot 1.8 protocol hack.
PvPLoggers now have skins!

Update to Minecraft 1.8.3

Fix npcs being temporarily invulnerable after spawn
Fix combat loggers being temporarily invulnerable after they login again

Update To Minecraft 1.8

Add a version checker