Limit action history size
Fix bugs
Add draw method on InputState
Implement MultiCell
Change protocell scope
Refactor input handlers for MultiCell
Implement alternative multicell selection
Add sprite preview
Fix cell cloning
Implement cell copying
Fix cell labels
Add borders
Add input for preview fps
Re-implement undo/redo for multicells
Add separate canvas for sprite preview
Implement json output generation
Fix page startup
Add zoom buttons
Fix cell clearing
Change scope of selectedCell