Merge branch 'dev' into f-update-own-password

CHANGELOG.md

README_SETUP.md

conf/core/server.conf

src/doc/specification/Authentication.md

src/doc/specification/Authentication.rst

src/main/java/org/caosdb/server/CaosDBServer.java

src/main/java/org/caosdb/server/ServerProperties.java

...ain/java/org/caosdb/server/datatype/DateTimeDatatype.java

src/main/java/org/caosdb/server/datatype/DoubleDatatype.java