Relaxed the type of input parameter for configuration.setExtendsFrom: Set -> Iterable. It's a small change, makes the API slightly better and it's backwards compatible.
Some tidy-up, removed a TODO (using notation parser gives standard error reporting, is consistent, etc.).
GRADLE-3124 Detect typos in map notation when configuring exclude rules on configurations.
Mentioned in the breaking changes section a validation of dependency exclude rules (configuration-level).