feature_core 1.1.0

Core classes and contracts for managing features.

1.1.0

• Breaking changes: new architecture in feature_core
• FeatureSource separated to: --- FeaturesContainer to save actual features --- FeaturesProvider to pull features from some source --- FeaturesManager to control and manage providers
• Abstract Feature renamed to FeatureAbstract and made constant, without any state

1.0.0

• Initial version.