Lay out some initial test requirements
Add tentative interfaces
Implement constrained value interface, create collection variant
Implement initial constraints & violations
Initial validator implementation
Add constraint factory interface and registry
Create constraint factories
Allow validation to bubble up (recursive validators)
Implement arrayaccses on ConstraintValueCollection
Constrain missing values, set defaults
Configure PHPUnit
Use is/with tastefully, create abstract violation
Move validator constraining in to validator constraint
Add configuration violation text and path infor
ConstrainedValueCollection recurses through children to find invalid values
Remove invalid child violations
Key validation tests
Add assertations
Implement array length constraints
Add default values and test