Add PluginAware.apply(Action)

With the deprecation of PluginContainer.apply(Class), non-Groovy-users are currently left with two unwieldy APIs: apply(Map) and apply(groovy.Closure).

I suggest adding PluginAware.apply(Action), similar to most other Gradle APIs. This way we can use Java 8 or Xtend lambda expressions for adding plugins.

Ask and ye shall receiveā€¦

I happened to be working in this area today.

Great, thanks! =)