factor out changing check into method
make sure that component resolved from changing dependency has changing flag enabled in metadata rule
added more tests for component metadata changing flag
use ProjectConfigurationActionContainer rather than `project.afterEvaluate` to register publications with ProjectPublicationRegistry
add some "allow" methods to maven/ivy repository fixtures
changed test to only compare file contents
changed tests to allow module metadata requests
make sure that maven snapshots are presented as changing to component metadata rules
fixed instantation of base plugin in unit test

- problem only surfaced when second parameter was added to constructor (Groovy substitutes null for missing single argument)