[web server] #1642893 issue a 403 instead of a 500 on Unauthorized exception To do so, we allow an arbitrary code to be passed to ``error_handler``. Default error code is still 500.

include *.py
include */*.py
recursive-include data *.gif *.png *.ico *.css *.js
recursive-include i18n *.po
recursive-include wdoc *