Clean theme / navigation menu / current course: a long shortname will be displayed over the main content

1. Add a file with a very long name in 1 word in your private files
2. Create a course with a very long shortname in 1 word
3. Rename a section to a very long name in 1 word
4. Add the block "Private files" to the course
5. Make sure that the following wrap over a few lines and does not overlap the content
   • The file name in the Private files block
   • The section name in the nav block
   • The course shortname in the nav block
   • The file in block private files

Repeat with very long names in a few words, and make sure they wrap as expected.