Support for Apache WebDAV module (#6510)
Support for Apache WebDAV module (#6510)

This change to the parser in `cloudstorage.lua` adds support for the [Apache WebDAV module][1]

It was manually tested using the [bytemark/webdav][2] docker container.

I developed this in Windows, with a docker container that hosted an extracted AppImage and a VNC server that I viewed using a VNC client.

I will write up my work flow at a later point.

Changes have not been tested against other webdav servers (what was this originally tested against?). Please could someone test against other webdav servers?

I also noticed a logic inversion error where we were looking for a slash at the end of the URL and if it exists, then we explicitly set `has_trailing_slash=false` - so I fixed it to set to `true`. I had to do this so that we weren't visiting the URL without a trailing slash - apache sends back a 301 redirect with a `location` header with a trailing slash, if you don't put a trailing slash.

As a side note, I think we should consider replacing this regexp pattern matching parser with the [XML parser in the newsreader plugin[3]

[1]: https://httpd.apache.org/docs/2.4/mod/mod_dav.html
[2]: https://github.com/BytemarkHosting/docker-webdav
[3]: https://github.com/koreader/koreader/blob/master/plugins/newsdownloader.koplugin/lib/xml.lua
pazos/koreader,NiLuJe/koreader,NiLuJe/koreader,poire-z/koreader,Markismus/koreader,koreader/koreader,poire-z/koreader,Frenzie/koreader,Frenzie/koreader,Hzj-jie/koreader,koreader/koreader,mwoz123/koreader