first version of the class version of the CanvasRenderer (WebGL one still to be done)

also re-organized the video folder and separated the canvas and webgl
implementation into two sub-folders
[#620] fixed a bunch of broken functions that were still calling the "old" static CanvasRenderer
[#620] couple of additional fixes (Thanks Jay)
implemented webgl renderer class. Platformer works
[#620] removed redundant code from the webGL renderer now that it inherits from renderer too
[#620] documentation fix
small clean-up before merge
Merge branch 'ticket-620'