Adopted 'agnostic' module. Ensured defaults are set before testing for missing attributes. Fixed indentation. Added getUids() convenience to UidRegistry. Renamed Nodes, Forks etc. Shifted LinearPage precalculations to #validate(). Stabilised draft of ChoicePageFork
Adopted 'agnostic' module. Ensured defaults are set before testing for missing attributes. Fixed indentation. Added getUids() convenience to UidRegistry. Renamed Nodes, Forks etc. Shifted LinearPage precalculations to #validate(). Stabilised draft of ChoicePageFork

cefn/avatap,cefn/avatap