Perform strict parsing of Sec-WebSocket-Version
Perform strict parsing of Sec-WebSocket-Version

The module previously used apr_atoi64() for its version parsing, which
allowed all sorts of version strings ("13blah", "+13", etc.).
parse_protocol_version() ensures that the header matches the RFC's ABNF.

jchampio/apache-websocket,jchampio/apache-websocket,jchampio/apache-websocket