Testing the log reader and change set to topic mapper using the new
LightweightTopicModel serializer. Functionality ok, except for classes
that are newly created between two versions.
Missed files in previous commit
fixed association of change sets to topics. For classes changed in
the logs which are not found in the src an error message is shown. This
only occured in some versions, need to find out better why classes are
not found. But does not fail or create any inconsistencies