Added many commands from Minecraft Java edition:
setblock
fill
seed
xp
gamemode spectator
summon
effect
difficulty
spawnpoint
setworldspawn
kick
enchant
All of the logic is contained inside of PlayerConnection.cpp along with the previous command handler, i also changed MobEffect.h to add a new helper for potion names -> ids.
And for spectator, a bunch of small changes inside server/client related file, along with the removal of the weird /spectator command which was added previously. I think it can still be refined because im not sure the invisibility thing is working.