nakedobjects-release artifact should not include plugins element

[dkhaywood]

My understanding is that nakedobjects-release is intended to be a convenience parent POM that groups together a consistent set of Naked Objects dependencies (dependencyManagement).

As shipped in 4.0.0 however it also includes a build/plugins section, and configures that the compiler-plugin (showDeprecations=false, showWarnings=false, executions phase for test-compile).

I don't think the artifact should be doing this; inheriting application POMs should configure compiler-plugin as they want.