adding the possibility to log to stdout

another exception

another exception

another exception

wider exception for <input> attribute "type" has invalid value

another exception for todylib

adding another ignore

another ignore for tidylib

adding a fffew other exception in tidylib

fix typo

html_tidy cleanup

ignoring another nav error

adding exception for <nav> tags in html validation

cleanup in html template + tidylib ...

* few small cleanup in html template (avoid empty tbody, put id between
quotes)
* switch to tidylib to validate the html instead of the previous hack
calling an external service (https://html5.validator.nu/)
* remove the previous validator script
* add exception for tidylib on empty <span> (these are required by
bootstrap)

fix html validator test for python 3

fix test and exception handling in code ...

With python 2 it was possible to do exception[0][...] to recover
details about an exception.
It's no longer authorized with python 3.
Now, we must do something like exception.args or exception.urls.
fortunately this syntax also works with python 2.
So we use it for both.

porting the tests over to python3

better behavior if user doesn't exist in one backend

code multi-backends setups tests + new unit test ...

* add a ldap+ad setup and code for direct, only AD manipulation
* add unit test for _deleteuser if it doesn't exist in all backends

adding slow_disabled decorator on html check unit tests

fix unit tests

fix many error with html unescaped attributes

fix many encoding errors on login and password

add unit test for login failure

better unit tests on authentication

small code reorganization ...

* extraction of exception decorator
* extraction of log handling

fix unit tests

adding unit test on selfmodify

remove trailing spaces

remove empty line