v1.0.7

Merge v1.0.7

- `PCanvasPainter`:
  - Added `zIndex` to define the painter layer. Previously was fixed to `0`.
- Added `PCanvasFactory`:
  - Allows extra platform dependent implementations: - `pixelsToPNG` and `pixelsToDataUrl`
- `PCanvasBitmap.toPNG`:
  - Ensure `singleFrame: true`

v1.0.3

Merge v1.0.3

- Fix `PColorRGB.a`.

v1.0.1

• Added interface WithDimension to PDimension and PCanvas.
• Added PCanvas.info.
• README.md: added usage example.

v1.0.0

1st version