Refactored all screens and connected them properly
Removed the special handling of the buttonClicked event
Introduced a wrapped screen as a helper to build screens wrapping other screens (like IfScreen or RepeatScreen)
Clean-up and fixed the initial random seed
Made root screen definition more data-like
Removed old to-do file
Implemented the first version of the "arrows" game rules
Corrected a missing case in the recognition of invalid arrow triangles
Some very hacky prototype implementation of hot-render-script reload