Removed lastConfidence code from AbstractAINode
Added code to copy constructor in Passive
Changed 'trace' to 'track' in all instances to avoid confusion
Removed checkIfTracedGotLost() (previous bug fix was undone)
Moved multicast code into Multicast classes

A new abstract type, Multicast, has been created to handle communication between AI nodes. Whereas previously there were communication policies implemented within the Abstract AI node, now these are separate classes which implement Multicast, placed within the epics.commpolicy package. This makes the code cleaner and easier to understand, as well as extend.