Remove !battle, will add something like it soon
Update maven shade plugin, update .gitignore to include IDEA files
Add config option to disable death messages
Don't send join/part messages from other channels.

When running MinecraftBot on an IRC bouncer to have the same username
for all channels, when a user joins any channel that the bouncer
account is connected to it will print send all the channels they joined
to the Minecraft servers. This commit solves this, and prevents a lot
of potential spam.