D-Net

#759 fixing maintaining action set identifiers in exporter module: when module does not get any input action set identifier does not have to be specified

removing empty package

fixing NPEx

setting confidence level to 1*factor when not specified

removing redundant code

throwing exception when mdstoreid or mdstore service location set to $UNDEFINED$ value

throwing exception when actionsetid set to $UNDEFINED$ value

introducing shared citation ExtraData XML model in icm-iis-common, implementing citation importer in mapred_import workflow, implementing exporter module

adding junit dependency for unit tests

introducing citations xstream deserialization tests