Use YAML syntax in config files
Define all exception classes int the top-level package
Do not modify the parsed conf object
plugins/admin: validate configuration
plugins/autojoin: validate configuration
plugins/rcon: validate configuration
plugins/topic: validate configuration
Move common conf key set validation to lib
plugins/command: validate configuration
plugins/pong: validate configuration
plugins/quit: validate configuration
Guarantee empty plugin confs are empty dicts
Move common value validation to t2jrbot.conf
plugins/rcon: server, port and password are optional