Add DEDA2020 DFA2 for uc2

uc2-application/README.md

...c/main/java/titan/ccp/aggregation/AggregationService.java

...rc/main/java/titan/ccp/aggregation/ConfigurationKeys.java

...aggregation/streamprocessing/ChildParentsTransformer.java

...tion/streamprocessing/ChildParentsTransformerFactory.java

...cp/aggregation/streamprocessing/JointFlatTransformer.java

...egation/streamprocessing/JointFlatTransformerFactory.java

.../ccp/aggregation/streamprocessing/JointRecordParents.java

...ccp/aggregation/streamprocessing/KafkaStreamsBuilder.java

...cp/aggregation/streamprocessing/OptionalParentsSerde.java

.../titan/ccp/aggregation/streamprocessing/ParentsSerde.java

...an/ccp/aggregation/streamprocessing/RecordAggregator.java

...tan/ccp/aggregation/streamprocessing/SensorParentKey.java

...cp/aggregation/streamprocessing/SensorParentKeySerde.java

...tan/ccp/aggregation/streamprocessing/TopologyBuilder.java

...c/main/java/titan/ccp/kiekerbridge/KafkaRecordSender.java

.../titan/ccp/kiekerbridge/expbigdata19/ConfigPublisher.java

...an/ccp/kiekerbridge/expbigdata19/ExperimentorBigData.java

...java/titan/ccp/kiekerbridge/expbigdata19/LoadCounter.java

...va/titan/ccp/kiekerbridge/expbigdata19/LoadGenerator.java