file

Describe the bug
在当前代码中，HEAD 请求的目标只能是文件，当 HEAD 一个目录时，会返回 404
https://github.com/cloudreve/Cloudreve/blob/4d7b8685b9d0c62d3c115cbe3450f69737f5a506/pkg/webdav/webdav.go#L236-L239

To Reproduce
Steps to reproduce the behavior:
HEAD http://example.com/dav/

Expected behavior
return 0, nil

Additional context
相关方法的 RFC 标准：
http://www.webdav.org/specs/rfc4918.html#rfc.sectio

Problem description

Hi, smart_open currently supports hdfs://, viewfs:// is also a hadoop file system which is similar to hdfs://.

I find that tf.io.gfile.GFile of tensorflow can support both hdfs:// and viewfs://, is it possible that smart_open add support for viewfs://?

Thanks~

Describe the bug

When using the editor, the buttons to save and cancel differ in order and appearance from the other buttons of the application.

To Reproduce

1. Open Filegator
2. Open the editor
3. See error

Expected behavior

The buttons should look the same and be in the same order as in the rest of the application.

Screenshots

Standard:
![NewFolder](https: