Merge branch 'dev' into f-doc-structure

CHANGELOG.md

README.md

doc/Query.md

src/main/java/org/caosdb/server/query/CQLLexer.g4

src/main/java/org/caosdb/server/query/CQLParser.g4

src/main/java/org/caosdb/server/query/POV.java

src/main/java/org/caosdb/server/query/TransactionFilter.java

src/test/java/org/caosdb/server/query/TestCQL.java