Allows for parsing either a shortcut component configuration by delegating to two
different component parses depending on the existence of the class attribute.
Extend
org.mule.config.spring.parsers.generic.ChildDefinitionParser to include
logic for identifying parent configuration element (since this only applies to "default"
elements there's an ugliness here - contradicitions (non-default children of configuration)
are avoided by the mule.xsd schema).
Used to parse shortcut elements for simple built-in components such as
org.mule.component.simple.BridgeComponent ,
import org.mule.component.simple.EchoComponent and
import org.mule.component.simple.LogComponent .