Redmine

The rouge gem claims to follow Semantic Versioning 2.0.0. As such, most releases of the gem in the past bumped the minor version.

I think it is not necessary to bump every minor release in our Gemfile, thereby forcing users on older Redmine releases to stay on an older rouge version unnecessarily.

As such, I think we should relax the rouge dependency to something like

gem "rouge", "~> 3.28" 

As with this change, people might have different languages available (as different rouge versions support different languages). Accordingly, I propose we also dynamically generate the list of highlighted languages (currently in public/help/code_highlighting_languages.html) with a controller action.