Handle GET and HEAD for a static file.
pathInfo ends with '/',
indexFile is automatically
added. In this case, Acceptable-Language: is also handled. Suppose
indexFile is index.html and if the value is ja,en, then
"index.html.ja", "index.html.en", and "index.html" are tried to be
opened in order.
pathInfo does not end with '/' and a corresponding index file
exist, redirection is specified in HTTP response.
Directory contents are NOT automatically listed. To list directory contents, an index file must be created beforehand.
The following HTTP headers are handled: Acceptable-Language:, If-Modified-Since:. (Range:, If-Range:, If-Unmodified-Since:)