upgraded gradle wrapper to 2.1
renamed default configuration in feature plugin to 'plugin', introduced property project.extensions.feature.configuration.
renamed feature -> eclipse-feature
introduced EclipseRepositoryPlugin
initial implementation of eclipse repository generation
started implementing multi-feature support in EclipseFeatureConfigurer
fixed inputs calculation in featureRemoveStalePlugins task
implementing skipping empty features
Merge branch 'master' into unstable
started design cleanup in EclipseFeatureConfigurer
finished design cleanup in EclipseFeatureConfigurer
started redesign of EclipseRepositoryConfigurer
stabilized implementation of EclipseRepositoryConfigurer