Migrate to WSGI
There are several reason to migrate to WSGI:
- allow to use one of the WSGI server for multi-process purpose
- remove pywebdav for wsgidav [1] for Python3 migration
After working on review92001, the idea is to base the development on werzeug [2] to allow routing extension.
[1] https://github.com/mar10/wsgidav
[2] http://werkzeug.pocoo.org/