Merge branch 'f-logging-segfaults' into f-debug-build

include/caosdb/exceptions.h

include/caosdb/logging.h

include/caosdb/status_code.h

src/caosdb/connection.cpp

src/caosdb/logging.cpp

src/caosdb/status_code_description.cpp

test/test_connection.cpp

test/test_data/test_caosdb_client.json

test/test_misc.cpp