Added getters and setters to the Assets classes

- Also started the tweening namespace
Moved getter properties closest to constructor
Added getters to the bounding object classes
Finnished modifying graphics modules to use getter and setter properties
Changed all the Input modules to use properties
Added getters and setters to the rendering namespace
Updated the sound namespace to use the new getters and setters
Finished the updating of all the endgate propertiy getters and setters
Added TimeSpan class, in process of adding it to the project
TimeSpan complete!