Merge branch 'feature/stream' into develop

.classpath

pom.xml

...a/info/textgrid/services/aggregator/AbstractExporter.java

src/main/java/info/textgrid/services/aggregator/REST.java

...a/info/textgrid/services/aggregator/SearchResultList.java

...va/info/textgrid/services/aggregator/html/HTMLWriter.java

...id/services/aggregator/teicorpus/TEICorpusSerializer.java

...grid/services/aggregator/tree/AggregationTreeFactory.java

...java/info/textgrid/services/aggregator/zip/ZipResult.java

...fo/textgrid/services/aggregator/SearchResultListTest.java