nitdoc: limit Sidebar menu indentation and clean CSS

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: topmenu responsive design for small resolutions

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: change color of <code> elements

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: generates doc for stdlib with nitc doc

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: short init with content for TplArticle

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: render anchor for empty sections

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: do not flatten mmodule view

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: introduce "All classes" sidebar in module page

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: TplDefinition::namespace is no longer mandatory

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: factorize more services into `MEntity`

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: better display of concerns

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: better display of section headers

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: generate a documentation page for all MGroup

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: generate a documentation page for all mproperties

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: auto hide source-link

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: update tests

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
nitdoc: avoid super-strings with null value in NitdocPage::tpl_graph

Quick fix for #540.

Signed-off-by: Alexandre Terrasa <alexandre@moz-code.org>
Merge: nitdoc_next

Some improvments on Nitdoc.

* better handling of projects in namespaces
* page for each MGroup/MProject
* page for each MProperty
* better display of concerns tree + ranking stub
* reviewed presentation for M*Def
* reviewed presentation for page headers
* "all classes" sidebar on MModule pages
* fix menu height and responsive features on menu
* general cleaning

Beta can be found [here for stdlib](http://gresil.org/jenkins/job/CI-nitdoc/ws/doc/stdlib/index.html) and [here for nitc](http://gresil.org/jenkins/job/CI-nitdoc/ws/doc/nitc/index.html).

Fixes: #400, #485 and #534.

Pull-Request: #537
Reviewed-by: Jean Privat <jean@pryen.org>