Sidebar: Adding Menu Items to the bottom of the sidebar

### Issue type

**I'm submitting a ...**

* [ ] bug report
* [x] feature request
* [ ] question about the decisions made in the repository

### Issue description

I am trying to add items to the bottom of the sidebar. I want to add secondary items (like a settings or about page link) to the sidebar menu items. What I want is that they do not appear in the list of menu items because they should be clearly distinguishable as secondary items for the users. Thus they should be at the bottom of the sidebar.

I managed to place items at the bottom and style them to resemble the default menu items. I used some CSS and added some HTML to the `OneColumnLayout` component. The problem that I can't solve is that my secondary menu items are not behaving correctly with the "compact" mode of the dashboard. The menu item text should not be visible but only the icon. However, when toggeling the sidebar to its normal size, the text should be visible again. I cannot use media queries to get this behaviour right. Either the text is visible in both situations or in none of them.

My question now is if there is any possibility to add these items in a non CSS/JS hacky way. If not, do you have a suggestion how to get it working correctly?

Thank you.

Node, 6.14.5
OS: all
Browser: all