Jellyfin-mpv-shim

This release adds update notifications and fixes various issues. Changes:

- Increase the timeout for logins. (99)
- If you were frequently getting "MPV Shim Login Failed", this should fix that.
- Add update check using GitHub. (50)
- Update checks happen when casting media by checking where the [GitHub releases page](https://github.com/iwalton3/jellyfin-mpv-shim/releases/latest) redirects to.
- If there is an update, you will only be notified once, until the application is restarted.
- You can disable this feature using the menu or the config file.
- Prepare application for translation. (68)
- [You can help translate the application here.](https://translate.jellyfin.org/projects/jellyfin/jellyfin-mpv-shim/)
- Clarify the "Always Transcode" option. (72)
- Add option to scale web client. (90)
- Shim mode now fixed in Flatpak. (89)
- Migrate from deprecated idle event to observer.
- Remove unused SyncPlay config options.

This release introduces SyncPlay support! It has been tested and is known to work on Windows and Linux. There are two ways to access SyncPlay functionality:

- Option 1: From the integrated Menu (press `c` or use the navigation controls on the mobile app).
- As always, you can navigate this menu using the arrow keys, enter to accept, and esc to go back.
- Option 2: You can also join existing SyncPlay sessions from the menu through the desktop app.

Joining syncplay sessions from other casting applications will start the media playing, but you still need to go into the menu to activate SyncPlay. You also need to use the menu to disable SyncPlay or create a new group. SyncPlay support is highly configurable. If you have problems, you may be able to adjust the algorithm using the config file to better suit your situation.

There were [a ton of changes](https://github.com/iwalton3/jellyfin-mpv-shim/commit/83c47e8ccc432ab57c96bfc865a83181957d98a0) within the project to facilitate this, and it is very possible I could have broken something. Please report any bugs.

Speaking of reporting bugs, this release now introduces the ability to log errors to disk. To enable it, edit the config file and set `write_logs` to `true`. You can also enable this through the settings menu. Please note you must restart the program for this to take effect. Log files also have API keys removed from them by default now. The release also contains a multi-server fix and webclient update.

This release introduces two major features for those who like video enhancement!

Shader Packs


MPV is known for having some of the most effective upscaler plugins, but these are difficult to install and switch between. The shader pack system allows creation of a profile of shaders and MPV configurations, which can be easily switched between. The menu system even allows you to reconfigure these settings while video is playing, without having to get off the couch!

The shader presets include FSRCNNX and Anime4K, which are two of the most effective video upscalers. You can read more about the profiles and contribute changes over at the [repository for the presets](https://github.com/iwalton3/default-shader-pack).

If you would like to customize or add your own presets, you can do so by enabling the `shader_pack_custom` option, which will copy the shader pack to your config folder and inhibit it from updating when you update MPV Shim.

SVP Integration


You can now change between SVP profiles from the built-in menu. No need to exit the media player and use a keyboard/mouse to change your motion interpolation settings. Unlike shader packs though, this requires configuration. Please see the README for details. This feature has been verified to work on Windows and Linux.

Other Fixes:
- Don't crash with unset subtitle language. (93)
- Make the settings button in the mobile app open settings.
- Upgrade web client. (Fixes issues with subtitles and stuck dialogs.)

This is a maintenance release. Changes:

- Upgrade pywebview to fix resize hang. (40)
- Upgrade web client to latest version.
- Prevent skipping videos when seeking too much. (83)
- Improve handling of direct path SMB urls. (84)
- Fix errors when websocket data is not a dict.
- Update resolution presets to real resolutions.

Changes:

- Make esc key exit fullscreen when no menu is open.
- Handle seq being null on Nightly. (63)
- Allow changing built-in keyboard shortcuts.
- Allow changing seek amount of arrow keys.
- Upgrade Windows MPV version to: [mpv-dev-x86_64-20200517-git-152b0e2](https://sourceforge.net/projects/mpv-player-windows/files/libmpv/mpv-dev-x86_64-20200517-git-152b0e2.7z/download)

This version allows you to optionally use HEVC instead of H264 for transcoded videos. This allows for better quality streaming or more concurrent users over a slow connection, provided the server has the processing power or acceleration hardware to be able to handle it.

You must enable this feature to avoid overloading servers that cannot handle it. You can enable the feature by [using the `c` menu](https://github.com/iwalton3/jellyfin-mpv-shim#menu) and restarting playback or by [editing the config file](https://github.com/iwalton3/jellyfin-mpv-shim#configuration).

Other Changes:

- Add ability to idle while paused and stop player when idle.
- Implement Pause and Unpause commands (55)