- Also adds it for users upgrading from older versions

- Workaround for ElementHost bug

- Infrastructure: use one HttpClient instance throughout the lifecycle
- Version update: rewrite the update service and add update prompt window
- Server sharing: add copy link button
- Dependencies: add ReactiveUI.Events.WPF, ReactiveUI.Fody, ReactiveUI.Validation, WPFLocalizeExtension, MdXaml

- Configuration: geositeDirectGroups + geositeProxiedGroups + geositePreferDirect
- PAC: rule generation using these new groups + cleanup

- Validate geosite group configuration
- Reset to default if specified group doesn't exist
- Regenerate pac.txt on version update (can be turned off)
- Cleanup of `Configuration` to separate loading logic and processing logic

- Remove StringEx.CS
- Update all dependencies
- Eliminate all warnings

- For OnlineConfigResolver and GeositeUpdater

Always sip002

- Compared to 2c15276: changed socketsHttpHandler to HttpClientHandler due to legacy .NET Framework
- Use System.Net.Http.HttpClient for GeositeUpdater
- New update check mechanism: first download checksum and compare, only download GeoSite DB on different checksum
- Verifiy downloaded GeoSite DB by comparing sha256sum before committing the change

also with some i18n update

revert fb4f7ea2eb

Implement "Show Plugin Output" checkbox.

- Split the file operations to new PACDaemon
- More precise matching logic for handling PAC content http request

When error code is SocketError.AccessDenied/10013(WSAEACCES), the port is reserved by system and you may not find the process name in `netstat`.
 https://github.com/shadowsocks/shadowsocks-windows/issues/1835#issuecomment-453528715

Fix #2140

Auto register hotkeys

- Portable mode ON: executable file's folder
- Portable mode OFF: current user's temp folder

* Translation
* Environment Variables support