Added unit and integration (Pax Exam based) tests for the fixed configuration behaviour in Rev. 798522
In Rev. 798529 adapted the ImmediateComponentManager to the new holder mechanism.
Rev. 798531 finally brings the big block of ComponentHolder and implementation.
The ComponentRegistry is refactored to be a factory for ComponentHolders and has no Configuration support. The ConfigurationComponentRegistry extends the ComponentRegistry adding support for Configuration from ConfigurationAdmin.
For ComponentFactory components the ComponentFactoryImpl also acts as the component holder. For Components without configuration (configuration-policy=ignore) UnconfiguredComponentHolder instances are used. This class is also used if no ConfigurationAdmin service is available.
For components taking configuration the ConfiguredComponentHolder class is used. This class can cope with singleton and factory configurations.
The Configuration policy "ignore" is handled by the ComponentRegistry in that an UnconfiguredComponentHolder is created to hold the component without ever forwarding configuration.
For Configuration policy "require" and "optional" a ConfiguredComponentHolder is used. The "require" policy is handled by the AbstractComponentManager to prevent activation if there is no configuration.