CHANGED: Import-/Export-Packages improved.
REFACTORED: New ConfigDescriptionListener(s) interface is used now.
FIXED possible NPE.

Signed-off-by: Michael Grammling <m.grammling@external.telekom.de>
FIXED wrong clean-up of config descriptions.

Signed-off-by: Michael Grammling <m.grammling@external.telekom.de>