* Fixed error that could happen on layers with certain processing setups (like masking without recoloring)
* Unified system for layer processing steps
* Renderer performance is logged to Perflog

* Expanded short form of gradient spec - any stop can be just a color; the offset would be auto-generated.
* Added ability to animate some layer properties
* Improved canvas animation performance a little (frame is skipped if previous is not done yet)

* Error reporting button not hidden during intro

  - small button in sidebar to display errors
  - copy all errors at once
  - limit of 100 errors
* Renderer errors that happen in callbacks not captured by SugarCube are logged
* 'Refresh caches' button in renderer debugger
* Split canvasmodel-utils.js from canvasmodel.js, making latter handle only CanvasModel code

* Renderer image loader can be customized (not used yet)