Merge: nitdoc: start using DocComponent rendering

This PR starts the migration of HTML rendering from old components to new DocComposite rendering.

Some minor differences can be seen in the output.

Démos: [stdli](http://gresil.org/jenkins/job/CI-nitdoc/ws/doc/stdlib/index.html) and [nitc](http://gresil.org/jenkins/job/CI-nitdoc/ws/doc/nitc/index.html).

Pull-Request: #1299
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>
Reviewed-by: Romain Chanoir <chanoir.romain@courrier.uqam.ca>