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.
Fixed Player.isOnline() returning true when the player isn't already logged in