Add warning raise when user bind sketch to canvas 

Add warning raise when user bind sketch to canvas with different graphics context.

So, if we initialize canvas with different context we can get some artifacts. This is depends from html canvas element, not from us.

P.S. Need to swap project version to 2.2.3-SNAPSHOT?
Why do we convert html element to clj object?  I don't think html element is a regular js object so converting to clj seems risky to me.