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

- 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

# Conflicts:
#	appveyor.yml
#	shadowsocks-csharp/Controller/Service/TCPRelay.cs
#	shadowsocks-csharp/Program.cs
#	shadowsocks-csharp/Properties/Resources.Designer.cs
#	shadowsocks-csharp/View/MenuViewController.cs
#	shadowsocks-csharp/packages.config
#	shadowsocks-csharp/shadowsocks-csharp.csproj

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