[mod_wstunnel] better Sec-WebSocket-Protocol parse
[mod_wstunnel] better Sec-WebSocket-Protocol parse

Improve handling of Sec-WebSocket-Protocol: binary, base64 for RFC6455.
When client sends Sec-WebSocket-Protocol in request header, client
may expect Sec-WebSocket-Protocol response.  mod_wstunnel is basic
tunnel endpoint and supports "binary" and "text" modes for RFC6455,
conventionally requested by client browsers as "binary" or "base64"

lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,lighttpd/lighttpd1.4,gstrauss/lighttpd1.4