Map the library to the specification

[roblarsen]

Ensure that we've covered everything here:

http://www.w3.org/TR/2dcontext/

Also, look for opportunities to add new stuff.

[roblarsen]

Right now Chrome says we don't have the following

• getLineDash
• isPointInStroke
• setAlpha
• setCompositeOperation
• setLineWidth
• setLineCap
• setLineJoin
• setMiterLimit
• clearShadow
• setStrokeColor
• setFillColor
• drawImageFromRect
• setShadow
• webkitPutImageDataHD
• webkitGetImageDataHD
• setLineDash

Firefox says:

• isPointInStroke
• canvas
• mozCurrentTransform
• mozCurrentTransformInverse
• mozFillRule
• mozDash
• mozDashOffset
• mozTextStyle
• mozImageSmoothingEnabled