Smart menu: highlight static internal links in the main menu

[HsH-Wolf]

If a static internal link is added to the main menu as smart menu, there is no highlighting as active page.

Steps to reproduce:

• Add a smart menu to the main navigation (inline, list)
• Add one item to this menu: an internal link (e.g. to a course) as static inline item
• click this menu item and see, that there is no highlighting

[HsH-Wolf]

referres to #620 und #384

[kaaermes]

as you can see in the second screenshot there is no active navigation marker for the active smart menu item "Internal link"