When trying to determine if a parameter is a dynamic projection parameter, i.e. the parameter of type Class that determines the projection to use, now the type parameter of that method parameter gets compared with the unwrapped return type. Therefore this works now not only for Maps and Collections but also for the various wrappers defined in QueryExecutionConverters.
Moved the method for unwrapping the return type from AbstractRepositoryMetadata to QueryExecutionConverters in order to make it available to every class needing it. This also puts it closer to the data it is working on.
Original pull request: #250.