Implement canvas canvas
Fix canvas graph dragging
re-write example
Implement canvas ellipse
Implement canvas line
Implement canvas text
Implement canvas path
code clean up
Implement canvas polygon
Implement canvas polyline
fix polygon position and bbox
getBBox take strokeWidth into account
Fix canvas polygon drawing
Support stroke-linejoin
Solve cache image blur issue
Only redraw shapes which are in dirty region.
Complete path implementation
Merge branch 'canvas'