redirect helper

Path grammar:  /<method>/<protocol>/<host>[/extra/path...]

  <method>   301 | 302 | 303 | 307 | 308   (or "30X" -> 302)
  <protocol> http | https
  <host>     target host, optionally host:port

The query string is preserved.

Examples:
  /302/http/www.example.com
  /301/https/evil.test/a/b?c=1
  /30X/http/169.254.169.254/latest/meta-data/