LMS-2134 ibrain2: improve error handling, remove project leader from the API

.../ch/systemsx/cisd/etlserver/AbstractStorageProcessor.java

.../java/ch/systemsx/cisd/etlserver/BDSStorageProcessor.java

...a/ch/systemsx/cisd/etlserver/DefaultStorageProcessor.java

...ch/systemsx/cisd/etlserver/hdf5/Hdf5StorageProcessor.java

...r/registrator/api/v1/IDataSetRegistrationTransaction.java

.../systemsx/cisd/etlserver/registrator/api/v1/IProject.java

.../cisd/etlserver/registrator/api/v1/IProjectImmutable.java

...ver/registrator/api/v1/impl/AbstractTransactionState.java

...sd/etlserver/registrator/api/v1/impl/ConversionUtils.java

...gistrator/api/v1/impl/DataSetRegistrationTransaction.java

...temsx/cisd/etlserver/registrator/api/v1/impl/Project.java

...d/etlserver/registrator/api/v1/impl/ProjectImmutable.java

...ystemsx/cisd/etlserver/registrator/api/v1/impl/Space.java

...a/ch/systemsx/cisd/openbis/generic/server/ETLService.java

...x/cisd/openbis/generic/server/business/bo/IProjectBO.java

...sx/cisd/openbis/generic/server/business/bo/ProjectBO.java

...msx/cisd/openbis/generic/shared/basic/dto/NewProject.java

...ic/shared/basic/dto/AtomicEntityOperationDetailsTest.java

screening/dist/etc/service.properties

...x/cisd/openbis/dss/etl/AbstractImageStorageProcessor.java