* 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)
The templates were html escaping the generated js code for the
autofill and the role management. This was breaking these features.
It's okay to not escape these as they are coming from a trusted source
(configuration file).
Also make the templates python3 compatible (not need to import Set in
python 3)
* add class to identify the 2 form columns
* add a js that calculate max width and resize all input-group-addon
spans
* load the js in the base template
