removed linked interface

vipra-cmd/src/main/java/de/vipra/cmd/Main.java

vipra-cmd/src/main/java/de/vipra/cmd/file/Filebase.java

vipra-cmd/src/main/java/de/vipra/cmd/lda/LDAAnalyzer.java

...-cmd/src/main/java/de/vipra/cmd/option/ImportCommand.java

vipra-cmd/src/main/java/de/vipra/cmd/text/Processor.java

vipra-rest/src/main/java/de/vipra/rest/model/Article.java

vipra-rest/src/main/java/de/vipra/rest/model/Linked.java

vipra-rest/src/main/java/de/vipra/rest/model/Topic.java

...ain/java/de/vipra/rest/provider/ObjectMapperProvider.java

...src/main/java/de/vipra/rest/resource/ArticleResource.java

...t/src/main/java/de/vipra/rest/resource/TopicResource.java

...in/java/de/vipra/rest/serializer/ArticleDeserializer.java

...main/java/de/vipra/rest/serializer/ArticleSerializer.java

...main/java/de/vipra/rest/serializer/TopicDeserializer.java

...c/main/java/de/vipra/rest/serializer/TopicSerializer.java

...t/src/main/java/de/vipra/rest/service/ArticleService.java

.../src/main/java/de/vipra/rest/service/DatabaseService.java

...est/src/main/java/de/vipra/rest/service/TopicService.java

vipra-ui/app/components/topic-link.js

vipra-ui/app/routes/topics/show.js