holyhttp-0.2

changes:

1. add support for chunked format
2. fix bug: unable to upload file
3. fix bug: response for static file request has wrong content (sometimes)
4. fix bug: directory traversal
5. fix bug: timer not work well (session-timeout, socket-timeout, ...)
6. use referer counter to avoid coredump when closing socket
7. add datetime in front of each log