BIS-1013: Improved disk space request.

...a/src/main/java/ch/ethz/sis/afsapi/api/OperationsAPI.java

...ava/src/main/java/ch/ethz/sis/afsapi/dto/ApiResponse.java

...server-java/src/main/java/ch/ethz/sis/afsapi/dto/DTO.java

...src/main/java/ch/ethz/sis/afsapi/dto/ExceptionReason.java

...erver-java/src/main/java/ch/ethz/sis/afsapi/dto/File.java

...rver-java/src/main/java/ch/ethz/sis/afsapi/dto/Space.java

...src/main/java/ch/ethz/sis/afsclient/client/AfsClient.java

...-server-javascript/src/js/api/server-data-store-facade.js

...stem/src/main/java/ch/ethz/sis/afs/api/OperationsAPI.java

...le-system/src/main/java/ch/ethz/sis/afs/api/dto/File.java

...e-system/src/main/java/ch/ethz/sis/afs/api/dto/Space.java

...ain/java/ch/ethz/sis/afs/dto/operation/OperationName.java

...n/java/ch/ethz/sis/afs/manager/TransactionConnection.java

...e-system/src/main/java/ch/ethz/sis/shared/io/IOUtils.java

...a/ch/ethz/sis/afsserver/server/impl/ApiServerAdapter.java

...java/ch/ethz/sis/afsserver/worker/proxy/AuditorProxy.java

.../ethz/sis/afsserver/worker/proxy/AuthenticationProxy.java

...h/ethz/sis/afsserver/worker/proxy/AuthorizationProxy.java

...ava/ch/ethz/sis/afsserver/worker/proxy/ExecutorProxy.java

...ain/java/ch/ethz/sis/afsserver/worker/proxy/LogProxy.java