added a kernel matrix visualizaion demo

[zhengyang92]

1. The demo can generate a simple toy data of sine function.
2. generate the heatmap using html5 canvas and overlying the map over the coordinate system.
3. there's a lot of improvement can be done, such as make a more powerful toy-data generator and have the contour drawn on the map.
4. I'll try to implement what I mentioned in 3 tomorrow.