Made Graphic2d's only draw children if they're visible

- Also compiled in accepted PR's into the generated endgate.js files

#4
Added tests to verify correctness of Graphic2d children Visible property being used correctly
Fixed Tween to trigger OnChange for all intervals of the tween

#5
Added tests to verify the correctness of how many times OnChange is triggered.
Disposed the MapManager on game dispose, this removes the map scenery canvas.

#12
Added test to verify that game dispose removes all used canvases from the dom
Added return value to the RotateAround function, it used to just return "any".
Added Grunt build
Added comments to generated files
Added comment on how to build with Grunt to the README.md
Updating products