Merge branch 'dev' into f-permission-checks

CHANGELOG.md

conf/core/server.conf

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

src/main/java/org/caosdb/server/resource/UserResource.java

.../org/caosdb/server/transaction/InsertUserTransaction.java

src/main/java/org/caosdb/server/utils/FileUtils.java

src/main/java/org/caosdb/server/utils/ServerMessages.java

src/main/java/org/caosdb/server/utils/Utils.java