Add an Artificial intelligence system

[SilverTiger]

Currently SilenceEngine provides most of the main features of a game engine, i.e. Gameplay mechanics, Rendering, Audio and Physics.

I think it would be a great enhancement to provide a system for artificial intelligence.
Something like a package com.shc.silenceengine.ai where you have a common interface for decision making like AISystem for further implementations like DecisionTreeAI, BehaviourTreeAI or RuleBasedAI for example.

[SilverTiger]

In the semester break I may have time to look into this and help with the implementation.

[lclc98]

I have done a bit of work on this, but I don't like the code i have written, but i would like to see a proper AI system