Add seafile user authentication.
List seafile directory.
Read file.
Write file.
Improve file writing.

* Assume content length is 0 if not set;
* Handle invalid file name better.
mkdir/move/copy/delete
A few improvements.

* Check write permission for repos.
* Don't allow usernames with "'".
Improve logging.
Add runfcgi command in command line.
Rename wsgidav.conf to settings.py and improve log message.
Add --daemon support.
Change script name to seafdav.
Config https option for built-in http server.
Add license.
Add missing seaf_utils.py
Convert repo.name to UTF-8.
add Makefile to packge source
added README
write pidfile in non-daemon mode
Return last modified time of files and improve MOVE.