Fix for Issue 35, added a note message on creating a new folder or updating an existi...

Fix for Issue 35, added a note message on creating a new folder or updating an existing folder, informing the user that slashes are not allowed in folder names.The same note is added during the update of file name. Also, the client code has altered in order to forbid the creation or the update of a resource name.At last, don't allow uploading a file which file name contains slash.