MockOutput now uses LatestMessages for xml messages.
Moved xml message encoding into RaceVisionByteEncoder. Removed XMLMessageEncoder.
Moved XML message sub types into an enumeration (XMLMessageType).
XMLMessage can now be queried for its attributes (like timestamp, length, etc...).
VisualiserInput now uses LatestMessages.
VisualiserInput now (as it did previously) uses switch statements for checking packet type, instead of if statements.
VisualiserRace now uses LatestMessages instead of VisualiserInput.
Race stores a reference to it. MockRace writes to it, and eventually, VisualiserRace will read from it.
Updated MockRace, MockOutput, Event to use it.
Angle now implements hashCode().
fjc40