Fixed an issue where hit didn't cached if a shape was cached before added to a layer. Fix #758
draw cache hit only when the shape was listening and visible
improve dragmove performance
Fix listening issue. close #772
fixed an issue where setPixelRatio changed canvas to wrong size
Improve getIntersection performance
fix #785: cache scaled twice in scaled canvas.
fix #785: cache scaled twice in scaled canvas.
Fix an issue where caching cached children is scaled twice
Merge branch 'fix-setPixelRatio'
Merge branch 'fix-listening'
Merge branch 'improve-dragmove-performance'
Merge branch 'performance-improvement'
Merge branch 'fix-cache-in-scaled-canvas'
Merge branch 'fix-cache-hit-before-added-to-layer'