Merge branch 'release/1.8' into develop
Does changing a property trigger KVC notifications? Test
Remove a value if you set the value to nil
Comply with key-value observing protocol
Tests include KVC
Observes only changes
Note about one change
Merge branch 'feature/key-value-observing' into develop
Build 574.8
Version 1.9
Merge branch 'release/1.9'