* Restructure and rename actor/renderers
* Rename cache flushing functions to reflect their scope
* Move canvas instance management to dedicated service
* Type resize-canvas-window Vue file
* Create cache for blended layers to speed up rendering on Documents with blended content
* Manage blend mode caching state through layer changes in Document canvas
* Comments updated
* Moving files around
* Omit invisible layers in snapshot rendering
* Add pausing to blend layer cache
* Cleanups and tests for LayerSprite
* Remove logs
* Use actual LayerSprite in test
* Simplify pending check
* Omit flush calls on (un)pausing of cache
* Extend tests for LayerSprite
* Update modifier key tooltip
* Create reusable function for invalidating blend cache
* Updated tests
* Allow partial cache flushes
* Ensure blended layer cache is flushed appropriately on undo
* Pause blend caching while rotating or scaling
* Fix for Safari rendering issues
* Renamed Selection data structure. Multiple select begins to work
* Saving and loading of multiple selection shapes implemented
* Renamed Document selection properties to avoid confusion
* Renamed and distributed functions between selection and shape utilities
* Fixes to selection toolbox
* Fixed issue with copying across multiple selections
* Final cleanups
* Selection outline is now rendered by interaction pane, not individual layer sprites
* Updated to zCanvas 4.3.1 to fix issue with bounding box detection on rotated content
* Refactored rectangles to always use left and top
* Layer scaling, rotating and mirroring is now a fast, synchronous operation
* Snapshots are now always of rendered layer content
