Implemented ability to show particle effects.
Paramaterized constants and ItemTable tests.
Switched to Lombok for message classes.

Lombok automatically generates constructors, getters, hashCode, equals,
and toString methods on the annotated classes at compile time. These can
be overridden where necessary. This should reduce maintenance load on the
message classes.
Added networking unit tests.

Signed-off-by: William Lebel <lebelwilliam@gmail.com>
Protocol test functionality and style fixes.
Added proxy support (fixes #114). Thanks @Johni0702!

Proxies such as BungeeCord have the option to forward the real address,
UUID, and properties from the auth process to the backing server so that
they can appear to be in online mode even if they are not.