Flysystem

Added

- [WebDAV] new adapter added

Fixed

- [Core] Trim slashed uniformly in the attribute classes.
- [Core] Uniformly use directory_visibility over visibility for directory usage.
- [FTP] export-ignore the test case.

Added

- [AzureBlobStorage] New adapter added

Fixed

- [AsyncAwsS3] Make EXTRA_METADATA_FIELDS protected to prevent error when extending the class

Fixed

- [FTP] Do not require setting of the root directory, use '' by default.

Fixed

- [FTP] Made connection resolving lazy again (1414)

Fixes

* [FTP] Support relative or empty connection root directories (1410)

Fixes

* [ZipArchive] delete top-level directory too when deleting a directory
* [GoogleCloudStorage] Use listing to check for directory existence (consistency)
* [GoogleCloudStorage] Fixed bug where exceptions were not thrown
* [AwsS3V3] Allow passing options for controlling multi-upload options (1396)
* [Local] Convert windows-style directory separator to unix-style (1398)