AXRController: Honor the applyingInstructions argument when selecting
Make HSSObject's _setIsA virtual and handle rules in HSSContainer
Ref: Output the first object/propertyName when there is no computed value yet
Fix crash when comparing instructions
Don't fill with defaults objects from object definitions
Add functions to iterate over rules
Keep track of the positions of the property defs to avoid overwriting w/ isA

When using isA: ref(), the value was received after some other property
definition which comes later had been stored, and then incorrectly
overwritten
Use the notify callback in the propertyChanged method
Set default and relayout when font changes
Adjust constness