One can now customize the default authentication method for all sub-domains,
i.e., either 'two_factor' or 'basic_auth' and define specific authentication
method per sub-domain.
For example, one can specify that every sub-domain must be authenticated with
two factor except one sub-domain that must be authenticated with basic auth.
ACLs can now be defined by subdomain AND resource using pattern matching
with regular expressions.
It allows a very fine-grained access control to backend resources.
[Note] For using example environmnent, user must update its /etc/hosts with
new subdomains updated in README.
Before this fix, the redirection URL was stored in the user session,
but this has a big drawback since user could open several pages in
browser and thus override the redirection URL leading the user to
be incorrectly redirected.