Nuxeo Drive Errors/Conflicts are not shown for duplicates

Steps to reproduce:

1. Install Nuxeo Drive 2.5.1
2. Wait for Sync complete
3. Server : Create 2 folders "a" and "A"
4. Client : Wait for sync completion
5. Observe the folder a is not created on the client side
6. Observe the following in the Drive logs:

   2017-08-21 14:55:01 99610 123145306136576 TRACE    nxdrive.engine.watcher.remote_watcher Processing event: {u'eventId': u'documentCreated', u'fileSystemItem': {u'userName': u'Administrator', u'lockInfo': None, u'name': u'a', u'canDelete': True, u'creator': u'Administrator', u'lastModificationDate': 1503320071255, u'canRename': True, u'canCreateChild': True, u'parentId': u'defaultSyncRootFolderItemFactory#default#618ac71d-9970-4c8d-870e-3b0c2687111b', u'path': u'/org.nuxeo.drive.service.impl.DefaultTopLevelFolderItemFactory#/defaultSyncRootFolderItemFactory#default#618ac71d-9970-4c8d-870e-3b0c2687111b/defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e', u'folder': True, u'creationDate': 1503320071255, u'lastContributor': u'Administrator', u'id': u'defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e'}, u'fileSystemItemId': u'defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e', u'fileSystemItemName': u'a', u'repositoryId': u'default', u'docUuid': u'80e35480-6232-4149-ad94-b9d95b4cb98e', u'eventDate': 1503320071255}
   2017-08-21 14:55:01 99610 123145306136576 DEBUG    nxdrive.client.local_client Ignoring banned file u'.DS_Store' in u'/Users/ffischer/NXDoiauze/Administrator'
   2017-08-21 14:55:01 99610 123145306136576 TRACE    nxdrive.engine.dao.sqlite Push to queue: remotely_created, pair=None
   2017-08-21 14:55:01 99610 123145306136576 TRACE    nxdrive.engine.queue_manager Pushing QueueItem[20](Folderish:True, State: remotely_created)
   2017-08-21 14:55:01 99610 123145306136576 TRACE    nxdrive.engine.queue_manager Pushed to _remote_folder_queue, now of size: 1
   2017-08-21 14:55:01 99610 140735218348032 DEBUG    nxdrive.engine.queue_manager Creating RemoteFolderProcessor
   2017-08-21 14:55:01 99610 123145306136576 DEBUG    nxdrive.engine.watcher.remote_watcher Marked doc_pair 'a' as remote creation
   2017-08-21 14:55:01 99610 123145306136576 DEBUG    nxdrive.engine.watcher.remote_watcher Remote recursive scan of the content of a
   2017-08-21 14:55:01 99610 123145302839296 DEBUG    nxdrive.engine.workers Thread RemoteFolderProcessor(123145302839296) start
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.dao.sqlite Acquired processor 123145302839296 for row 20
   2017-08-21 14:55:01 99610 140735218348032 DEBUG    nxdrive.engine.engine Checking sync completed: queue manager is active, overall size = 0, empty polls count = 0, local watcher empty events = 1, blacklist = 0, not Windows
   2017-08-21 14:55:01 99610 123145302839296 DEBUG    nxdrive.engine.processor Executing processor on <StateRow[20] local_path=u'/Administrator/a', remote_ref=u'defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e', local_state=u'unknown', remote_state=u'created', pair_state=u'remotely_created'>(0)
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.processor Calling <bound method Processor._synchronize_remotely_created of <Processor ID=123145302839296>> on doc pair <StateRow[20] local_path=u'/Administrator/a', remote_ref=u'defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e', local_state=u'unknown', remote_state=u'created', pair_state=u'remotely_created'>
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.processor Soft locking: /Administrator/a
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.processor readonly unlock: unlock on /Administrator with 2
   2017-08-21 14:55:01 99610 123145302839296 DEBUG    nxdrive.engine.processor Creating local folder 'a' in '/Users/ffischer/NXDoiauze/Administrator'
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.processor readonly lock: update lock count on /Administrator to 0
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.processor readonly lock: relocked path: /Administrator with 2
   2017-08-21 14:55:01 99610 123145302839296 DEBUG    nxdrive.engine.workers Give up for error [DEDUP] (None) for <StateRow[20] local_path=u'/Administrator/a', remote_ref=u'defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e', local_state=u'unknown', remote_state=u'created', pair_state=u'remotely_created'>
   2017-08-21 14:55:01 99610 123145302839296 DEBUG    nxdrive.engine.queue_manager Giving up on pair : <StateRow[20] local_path=u'/Administrator/a', remote_ref=u'defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e', local_state=u'unknown', remote_state=u'created', pair_state=u'remotely_created'>
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.processor Removing local_path on <StateRow[20] local_path=u'/Administrator/a', remote_ref=u'defaultFileSystemItemFactory#default#80e35480-6232-4149-ad94-b9d95b4cb98e', local_state=u'unknown', remote_state=u'created', pair_state=u'remotely_created'>
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.processor Soft unlocking: /administrator/a
   2017-08-21 14:55:01 99610 123145302839296 TRACE    nxdrive.engine.dao.sqlite Released processor 123145302839296
   2017-08-21 14:55:01 99610 123145302839296 DEBUG    nxdrive.engine.workers Thread RemoteFolderProcessor(123145302839296) end
   

7. Observe no error is show on the graphical interface
8. Now click the pause button
9. Observe an error is shown (see errorAfterPause.png)