Continued flock work.

add actual locking and log changes necessary for debugging.

Simpler log unique id.

Respect locked files, surface correct exception.

Conflicts:
	lib/private/connector/sabre/file.php

Remove unused methods.

Conflicts:
	lib/private/files/storage/local.php

Fix typo

Fix typo

Removed unused vars/declarations, update PHPDoc.

Don't error out on console.

Move Lock to private namespace, add interface. Update PHPDoc.

Restore the reference to this used exception class.

make sure to close the stream at the end of each test

Normalize lock exception messages.

don't ask for fileInfo if we already have one

Conflicts:
	apps/files_encryption/lib/proxy.php

name the storage wrapper to make sure that we don't apply the wrapper multiple times

Conflicts:
	lib/private/util.php

fix unit test after adding the additional parameter to addStorageWrapper()

only lock if unlink is called for a file

Can't use assertInstanceOf on wrapped storage; use assertTrue(instanceOfStorage() instead.

Conflicts:
	tests/lib/files/filesystem.php

Use ->instanceOfStorage() not instanceof for Storage instances.

Conflicts:
	lib/private/helper.php

get the storage from the view

Conflicts:
	apps/files_encryption/tests/webdav.php

workaround to get the unit test going

Conflicts:
	apps/files_encryption/hooks/hooks.php

Added isLocal() method to storage, used for xsendfile

Added isLocal() method to Storage to find out whether the storage is
local or not.
This method is used for the x-sendfile logic to find out whether to add
the headers.

Conflicts:
	lib/private/files.php

Add ->instanceOfStorage to handle instanceof for storage wrappers

Conflicts:
	lib/private/files/storage/common.php
	lib/private/files/storage/wrapper/wrapper.php
	lib/public/files/storage.php

Use instanceOfStorage instead of instanceof

Conflicts:
	lib/private/files.php

Fix storage wrapper being called with null

Pass any methods custom to specific storage implementations to the wrapped storage

remove duplicate declaration of isLocal()

remove file locking - code will continue to live in it's own app
added missing LockNotAcquiredException
Dont backport unit tests for code that isn't backported
fix failing unit test
Merge pull request #8885 from owncloud/flock-stable6

[stable6][WIP] Move Flock basics into stable6