Rewrite for nginx 1.26.3

Complete rewrite targeting nginx 1.26.3.

• SOCKS5 username/password authentication
• SSL to upstream through SOCKS tunnel
• IPv4/IPv6 address types
• Crash fix when SOCKS proxy is down

Added socks_set_host directive

v1.1

A typo fix

Support 1.9, 1.10, 1.11 branches up to current nginx version

v1.0

Better README formatting