Added Body, Engine, Velocity

This is a draft of the structure of the Engine subsystem. The engine
controls the iterative simulation of the solar system. Body and
Velocity are models of celestial bodies and velocity vectors
respectively.
Created the BoundingBox model

This model is used to wrap around an object and identify the area that
the object occupies. Using the static function isIntersecting(), one
could tell if two boxes are occupying the same space.
Implemented collision detector algorithm

Exponential time algorithm to check if each body is colliding with
another.
Implemented Body Model

Added constructors, updatePosition(), added members
gravityInfluenceRangeOffset and radius.
Fixed detection bug

Fixed bug where detection where the other space components where not
considered in the intersection.
Merge pull request #1 from Troy-CS-3332-TRAA/Collision-Detector---Implementation

Collision detector   implementation