This refactoring aims to ease testability and clean up a lot of soft touchy
typings in test code.
This is the first step of this refactoring introducing the concept and
implementing missing interfaces and stubs. At the end of the day,
ServerVariablesHandler should completely disappear and every variable should
be injected in the endpoint handler builder itself.
Sometimes, LDAP organization is such that groups membership cannot be computed
with username only. User DN is required to retrieve groups.
e.g. user Joe has a username joe and a cn of Joe Blogs, resulting in a dn of
cn=Joe Blogs,ou=users,dc=example,dc=com which is needed to retrieve groups
but cannot be computed from joe only.
Issue was reported in issue #146
Previously, string "{0}" was replaced by the user dn in the groups_filter
attributes of the LDAP configuration.
However, if the groups children only have a memberUid attribute, one would
like to use the username instead of the user dn.
Since the user dn can be built from the username, "{0}" is now replaced
by the username instead of the user dn so that an LDAP relying on attribute
'memberUid' can be used.
One can now plug its own SMTP server to send notifications
for identity validation and password reset requests.
Filesystem has been removed from the template configuration file
since even tests now use mail catcher (the fake webmail) to
retrieve the email and the confirmation link.
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.
