Refine PAC server

- Uncompress the text file for better version control
- Touch the PAC files in first place

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

Update the PAC file using the proxy channel only when proxy mode is enabled.

Support local IPv6 listener

# Conflicts:
#	shadowsocks-csharp/Model/Configuration.cs

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

Marked ApplicationRestartFlags with Flags attribute

DumpRegisteredEncryptor

PAC will check the user rules first to find whether the URL should be connected via PROXY or DIRECT. If it does not match, then go to check GFWList rules.

Register restart after system reboot, #2154

Update the system proxy when user-rule.txt changed

Fix #2140

binary modified via OD with tray icon function calls bypassed

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>

Cause: process's additional environment variables are not expanded
by correctly.

Innovated by studentmain (StudentEx <scncgz@gmail.com>)

Auto register hotkeys